Cr2O3 + 2Al→ 2Cr + Al2O3
(a)Calculate the mass of aluminium need to react with I tonne of chromium (III) oxide.
(b) Calculate the mass of chromium produced from I tonne of chromium (III) oxide.
To solve this problem, we need to use the balanced chemical equation given in the question to determine the relative amounts of the reactants and products. The balanced chemical equation is:Cr2O3 + 2Al → 2Cr + Al2O3We are given that the starting amount is 1 tonne of chromium (III) oxide (Cr2O3), and we want to calculate the mass of aluminium needed to react with this amount. From the balanced equation, we can see that for every 1 mole of Cr2O3 that reacts, 2 moles of Al are needed.1 tonne is equal to 1000 kg, and the molar mass of Cr2O3 is 151.99 g/mol, so 1 tonne of Cr2O3 is equal to 1000 / 151.99 = 6.58 moles of Cr2O3. Since 2 moles of Al are needed for every 1 mole of Cr2O3, 6.58 moles of Al are needed to react with 1 tonne of Cr2O3.The molar mass of Al is 26.98 g/mol, so 6.58 moles of Al is equal to 6.58 x 26.98 = 179 kg of Al. Therefore, the mass of aluminium needed to react with 1 tonne of chromium (III) oxide is 179 kg.To calculate the mass of chromium produced, we can use the same method. From the balanced equation, we can see that for every 1 mole of Cr2O3 that reacts, 2 moles of Cr are produced. Since 1 tonne of Cr2O3 is equal to 6.58 moles, 6.58 x 2 = 13.16 moles of Cr are produced.The molar mass of Cr is 52 g/mol, so 13.16 moles of Cr is equal to 13.16 x 52 = 687 kg of Cr. Therefore, the mass of chromium produced from 1 tonne of chromium (III) oxide is 687 kg.
The balanced chemical equation provided in the question must be used to calculate the proportions of the reactants and products in order to answer this issue. Al2O3 + Cr2O3 = Cr2O3 + Al2O3 is the balanced chemical equation.
Given a starting amount of 1 tonne of chromium (III) oxide (Cr2O3) and need to determine how much aluminum is required for the reaction to occur.
We can see from the balanced equation that 2 moles of Al are required for every 1 mole of Cr2O3 that reacts. Given that 1 tonne is equivalent to 1000 kg and that Cr2O3 has a molar mass of 151.99 g/mol, 1 tonne of Cr2O3 is equal to 6.58 moles of Cr2O3.
In order for 1 tonne of Cr2O3 to react with 6.58 moles of Al, 2 moles of Al must be added for every mole of Cr2O3.6.58 moles of Al are equivalent to 6.58 x 26.98, or 179 kg, of Al since the molar mass of aluminum is 26.98 g/mol.
As a result, 179 kg of aluminum is required to react with 1 tonne of chromium (III) oxide.
We may apply the same procedure to determine the mass of chromium produced. The balanced equation shows that 2 moles of Cr are created for every mole of Cr2O3 that reacts.
Because 1 tonne of Cr2O3 is equivalent to 6.58 moles, the amount of Cr produced is 6.58 x 2 = 13.16 moles.
13.16 moles of Cr are equal to 13.16 x 52 = 687 kg of Cr since the molar mass of Cr is 52 g/mol. Consequently, 687 kg of chromium is created from 1 tonne of chromium (III) oxide.
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which of the following molecules has a central atom with sp3 hybridization? x. becl42- y. sf4 z. bro3-
Only BeCl4^2- has a central atom with sp3 hybridization. The other molecules, SF4 and BrO3-, do not have a central atom with sp3 hybridization.
When it comes to identifying which of the following molecules has a central atom with sp3 hybridization, the answer is X. BeCl4^2-. This molecule has a central atom of beryllium, which has an electron configuration of [He] 2s^2 2p^1. In order to form a stable structure, the beryllium atom must use sp3 hybridization, which is a combination of one s orbital and three p orbitals. This hybridization allows the beryllium atom to form four single covalent bonds with the four chlorine atoms, resulting in a tetrahedral shape.
The other molecules, Y. SF4 and Z. BrO3-, have central atoms of sulfur and bromine, respectively. Both of these atoms have an electron configuration of [Ne] 3s^2 3p^4. This allows them to form a stable structure without needing to use sp3 hybridization. Instead, sulfur forms a seesaw shape using sp3d2 hybridization, while bromine forms a trigonal bipyramidal shape using sp3d2 hybridization.
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a sample of carbon dioxide gas collected at a pressure of 204 mm hg and a temperature of 298 k has a mass of 59.9 grams. the volume of the sample is l.
After solving the equation the volume of the sample is 121.967L.
What is ideal gas equation?
The Ideal Gas Law (also known as the General Gas Equation) states that the pressure, volume, and temperature of an ideal gas are related through the equation PV = nRT, where P is the pressure, V is the volume, n is the number of moles of the gas, R is the ideal gas constant, and T is the absolute temperature. This equation is useful for understanding the behavior of gases and for calculating the amount of gas present in a given volume at a given temperature and pressure.
Using ideal gas equation
PV=nRT
V=nRT/P
n=59.9/44 =1.361 mol
V=[ 1.361×62.3636LmmHg/Kmol×293.15K]÷ 204 mm hg
=121.967L
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The volume of the sample is 121.967L.
Define the ideal gas law.
The ideal gas law, also known as the perfect gas law, is a relationship between a gas's pressure P, volume V, and temperature T in the range of low pressures and high temperatures where the gas's molecules move virtually independently of one another.
The ideal gas law (PV = nRT) connects the macroscopic characteristics of ideal gases. An ideal gas is one in which the particles are both non-repellent and non-attractive to one another (have no volume).
Using ideal gas equation
PV= nRT
V= nRT/P
n= 59.9/44 =1.361 mol
V=[ 1.361×62.3636LmmHg/Kmol×293.15K]÷ 204 mm hg
=121.967L
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Which of the following compounds contains both ionic and covalent bonds?A SO3B C2H5OHC MgF2D H2SE NH4Cl
The bonds ionic and covalent are in the NH4Cl as it has the one ionic bond and 3 covalent bonds.
There is definitely a coordinate bond (that's definitely a type of covalent bond wherein handiest one of the collaborating atoms donate each in their electrons to shape a covalent bond) among lone pair of nitrogen in ammonia(NH3) and a proton(H+ ion),which as a result creates an ammonium ion(NH4+).
Further this ammonium ion because of a high quality fee bureaucracy an ionic bond with chloride ion(Cl–).So definitely there are:-3 natural covalent bonds in NH3.a coordinate bond(which is likewise a covalent bond) among NH3 (ammonia)and H+ ion(proton).And of route an ionic bond among NH4+ (ammonium ion) and Cl–(chloride ion).Read more about ionic;
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What is the volume of a 1.25 M solution
if it contains 42 grams of sodium
hydroxide.
Volume NaOH = [?] mL
Answer:
You could calculate the answer given the formula
M = mol/L
you can get mol using g/MolarMass
=> 42g/22.99g/mol = 1.82688125mol
1.25M = 1.82688125mol/V
=> apply simple algebra
V = 1.4615 L
=> Notice that the answer requires the unit to be ml
V = 1.4615L * 1000ml/L = 1461.5ml
=> Notice that the given grams have 2 sig figs
V = 1500 ml
In conclusion, write down at least two pieces of evidence showing that Earth’s atmospheres or oceans have changed over time. Provide reasoning for each piece of evidence.
The evidence that is showing that Earth’s atmospheres or oceans have changed over time.
The planet progressively cooled over a very long period of time, millions of years. Water vapor turned from a gas to a liquid when the temperature fell low enough. The result was clouds. The oceans were created from these clouds, and the oceans absorbed a significant amount of the atmospheric carbon dioxide.How has Earth's atmosphere changed over time?Humans have dramatically changed the composition of the atmosphere and increased the amount of greenhouse gases in the environment since the industrial revolution. Long-term changes in our climate result from these gases' ability to make the atmosphere act more like a greenhouse and store more heat.
By condensation from the solar nebula, Earth was created 4.54 billion years ago, or roughly one-third the age of the universe. The primeval atmosphere was likely produced by volcanic outgassing, and others.
Therefore, Due to plant photosynthesis, the amount of oxygen rose. As ammonia reacted with the newly generated oxygen in the atmosphere to create nitrogen and water vapor, its proportion in the atmosphere fell. As it combined with the freshly created oxygen to create carbon dioxide and water, the amount of methane reduced.
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A tumor marker is being developed to detect early breast cancer. Of the 400 women who volunteered for the study, 350 tested negative for the marker. Of these women, three developed breast cancer. The 50 women who tested positive for the marker underwent further tests, of these 50 women, 48 were diagnosed with early breast cancer, and the other two women were found to not have breast cancer. Use enclosed excel sheet for your answers (including your calculations)
While tumor marker test results can be useful, they are not conclusive. A low result does not imply that you do not have cancer or that you are in remission.
CA 15-3, for example, is raised in less than half of patients with early breast cancer and in more than 80% of those with metastatic breast cancer. Three tumor markers, cancer antigen 15-3 (CA 15-3), cancer antigen 27.29 (CA 27.29), and carcinoembryonic antigen (CEA), have been used in breast cancer care to help monitor metastatic breast cancer (advanced disease), but they have not been found to be useful in detecting a breast cancer recurrence or extending lives. If the level falls, the treatment is effective. If it rises, the cancer may be spreading.
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Magnesium reacts with hydrochloric acid in a sealed container, as shown. The initial pressure inside the container is 1.20 atm and its volume is 100 mL. What is the pressure inside the container after 243 mg of magnesium has reacted? (Note: Assume the reaction is isothermal and the gas behaves ideally.)
Mg(s) + 2HCl(aq) â MgCl2(s) + H2(g)
(30 degrees celsius)
3.6 atm is the pressure inside the container after 243 mg of magnesium has reacted.
In plain English, what is pressure?Pressure is defined as the force applied perpendicularly to an object's surface divided by the area over which that force is applied.
The reaction given is: Mg(s) + 2HCl(aq) → MgCl2(s) + H2(g). The moles of H2 gas formed are therefore equal to the moles of Mg that reacted, and can be calculated from: n = 0.243 g/(24.3 g/mol) = 0.01 moles (converting 243 mg to 0.243 g).
The added pressure is calculated by P = nRT/V using approximations: 0.08 L atm/molK for R (0.0821 rounded), 300K for T (303.15 before rounding) and 0.10 L for V.
Solving gives pressure = 2.4 atm. Finally, this number must be added to the initial pressure: 2.4 + 1.2 = 3.6 atm.
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If we represent the equilibrium as:
CoCl 4
2−
(aq)⇌Co 2+
(aq)+4Cl −
(aq)
We can conclude that: 1. This reaction is exothermic. endothermic. neutral. More information is needed to answer this question. 2. When the temperature is decreased the equilibrium constant,
K
: increases. decreases. remains the same. More information is needed to answer this question. 3. When the temperature is decreased the equilibrium concentration of
CoCl 4
2−
: increases. decreases. remains the same. More information is needed to answer this question. At high temperature the red color is strong. At low temperature the gas has less color. If we represent the equilibrium as:
2NO 2
(g)⇌N 2
O 4
(g)
We can conclude that: 1. This reaction is exothermic. endothermic. neutral. More information is needed to answer this question. 2. When the temperature is decreased the equilibrium constant,
K
: increases. decreases. remains the same. More information is needed to answer this question. 3. When the temperature is decreased the equilibrium concentration of
N 2
O 4
: increases. decreases. remains the same. More information is needed to answer this question. At high temperature the red color is strong. At low temperature the gas has less color. If we represent the equilibrium as:
N 2
O 4
(g)⇌2NO 2
(g)
We can conclude that: 1. This reaction is exothermic. endothermic. neutral. More information is needed to answer this question. 2. When the temperature is increased the equilibrium constant,
K
: increases. decreases. remains the same, More information is needed to answer this question. 3. When the temperature is increased the equilibrium concentration of
N 2
O 4
: increases. decreases. remains the same. More information is needed to answer this question.
For a first reaction its exothermic reaction ,increases, decreases.
For second reaction its exothermic reaction, increases, decreases.
For third reaction its endothermic reaction , increases, decreases.
What principle underlies Le Chatelier?
Le Chatelier's principles, sometimes known as the equilibrium law, allow for the prediction of a system in chemical equilibrium (such as the change in temperature or pressure).
The equilibrium position moves to the right at low temperatures.
Please see the accompanying file for a more thorough explanation.
CoCl₄²⁻ (aq) ⇆ Co²⁺ + 4Cl⁻
1. Exothermic -
At low temp, the position of equilibrium shifts to right side and forms more pink color.
when the temp decreases. the K increases
[tex]K = \frac{[Co^{2+} ][Clx^{-} ]^{4} }{CoCl_{4} ^{2-} }[/tex]
2. At low temperature, more Co²⁺ produces and K values will increase as equilibrium shifts towards right.
Higher [Co²⁺] = Hugh K value
3. When temperature decreases the concentration of CoCl₄²⁻ decreases.
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For a particular process, q = 25 kJ and w = –15 kJ. Which of the following statement(s) is/are true?
A. Work is done by the system on the surroundings.
B. The temperature of the surroundings increases.
C. The internal energy of the system increases.
D. The process is exothermic.
E. Statements A and B are true.
F. Statements A and C are true.
G. Statements C and D are true.
For the given question, statements A and B are true. So, Option E is correct as the work done given is negative.
How to calculate the work done with respect to the surroundings?According to the First Law of Thermodynamics, energy can only be changed from one form to another through the interplay of heat, work, and internal energy. Under no circumstances can energy be created or destroyed. It can be represented as:
ΔU = q + w
where,
ΔU = Total internal energy of the system
q = the heat that is transferred from a system to its surroundings
w = work done on the system or by the system
It is given in the question that q = 25 kJ and w = -15 KJ
So we get from the above equation-
ΔU = 25 - 15 = 10 KJ
The negative amount of heat that the environment has absorbed will be the value of internal energy.
Thus, the negative sign of work done shows that the work is done by the system on the surroundings while increasing the temperature of the surroundings.
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Which of the following reactions releases most energy to the surroundings?
A Reaction energy change = -456 kJ
B Reaction energy change = +547 kJ
C Reaction energy change = -38 kJ
D Reaction energy change = +1456 kJ
Also give reason
The Reaction energy change = -456 kJ releases most energy to the surroundings. Option A is correct here
What is a chemical reaction?In a chemical reaction, one or more substances—also known as reactants—are changed into one or more additional substances—also known as products. Chemical elements or chemical compounds make up substances.
Chemical reactions are the processes by which a substance or substances change chemically to create a new substance or substances with entirely new attributes. The most energy is released into the environment via the reaction energy change, which is -456 kJ.
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which of the following statements is (are) true? correct the false statements it is impossible to satisfy the octet rule for all atoms in xef
The first and third statements are correct, impossible for every atoms in xef to satisfy this same octet rule.
What is octet rule?
The octet rule is a general chemical principle that represents the idea that main-group elements have a propensity to connect in a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.
TRUE
The octet rule is not followed by Xe. In fact, it creates ties. It can accommodate more than 8 electrons.
Since Xenon has valence electrons at the fourth energy level, it can reach the fourth sublevel, which gives it access to more than eight electrons. The Xenon is surrounded by 3 lone pairs and 2 bonded pairs of valence electrons in XeF2, which is dsp3 hybridised. The VSEPR forecasts the form to be linear.
The d sublevel is not accessible to elements in the first two periods of the Periodic Table, and they are instead required to abide by the octet rule (or duet H and He rule).
False. (b)
Due to its electrical arrangement of 1s2, 2s2, and 2p4, oxygen is tiny and does not have a vacant d-orbital.
(c) TRUE
Stronger bonds result from stronger bond orders. The bond strength will also be lesser the longer the bond is. One can tell that the NO+ bond will be stronger if they compute the bond order, which is greater for NO+ and the bond length, which is greater for NO-.
D. FALSE
Due to Covalency, the three oxygen forms are bonded. The double bond and single bond will switch places if you design a resonant structure, but in reality, no resonating form can fully explain the structure of ozone; the behaviour of the bond is the average of a single bond and a double bond between the oxygen atoms. There is neither a weaker nor a stronger bond in ozone because both bonds are equivalent.
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Complete the paragraph to describe precipitation reactions.
Chemical precipitation occurs when a product is
and precipitates out of a solution. By comparison, precipitation reactions require the reactants to be
in the solvent.
Chemical precipitation occurs when a product is insoluble and precipitates out of a solution. By comparison, precipitation reactions require the reactants to be soluble in the solvent.
What is Chemical precipitation ?Chemical precipitation is a type of chemical reaction in which a solid substance is formed from the reaction of two or more dissolved chemicals. In a chemical precipitation reaction, ions from the reactant solutions combine to form a new compound that is insoluble in water, causing it to "precipitate" or settle out of the solution as a solid. Chemical precipitation reactions are often used in the laboratory to purify and isolate compounds, as the solid precipitate can be easily separated from the liquid solution using techniques such as filtration or centrifugation. The formation of a solid precipitate is typically indicated in a chemical equation by the presence of a (s) notation after the product.To learn more about Chemical precipitation refer :
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Answer: 1.) insoluble 2.) soluble
Explanation: EDMENTUM
The unit cell in a certainlattice consists of a cube formed by an anion at each corner, ananion in the center, and a cation at the center of each face. The unit cell contains a net: Question 8 answers
5 anions and 6cations
5 anions and 3cations
2 anions and 3cations
3 anions and 4cations
2 anions and 2cations
Lattice structures: The correct answer is 2 anions and 3 cations. The unit cell contains a net 2 anions and 3 cations
What are lattice structures?
A lattice structure is a unit cell that fills all available space and may be tessellated along any axis without any spaces between the cells. These structures are a new development in terms of weight, energy, and time savings in modern manufacturing.
Anions are present at 8 corners and in one corner contribution is 1/8
so for 8 corners =(1/8)×8=1
And one anion i at centre and its contribution is one
total anion=2
Cations are present at 6 corners and contribution of one face is 1/2
So, net number of cations is 6×1/2 = 3 cations.
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The unit cell contains a net 3 cations and 2 anions.
Lattice structures: what are they?
A unit cell that completely occupies its area and can be tessellated along any axis without any gaps between the cells is known as a lattice structure. In terms of weight, energy, and time savings in modern manufacturing, these structures represent a new advance.
Corner atoms are counted as 1/8 of a total atom (just 1/8 of them are inside the unit cell's boundaries).
Atoms in the center count as one whole (whole thing inside the unit cell)
Face atoms are counted as one-half of a unit cell (half inside, half outside).
Therefore, the computation for anions is
1/8 anion at each corner x 8 corners on a cube = 1 anion
+ 1 whole anion
= 2 anions per cell
The formula for cations is
1/2 cation at each face x 6 faces on a cube = 3 cations per cell
The unit cell contains a net 3 cations and 2 anions.
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Arrange the following gases in order of increasing density (hlghest denslty at the bottom of the list) under the conditions given. Assume that the volume of the contalner Is not fixed. Place these In the proper order: Hellum at 1atm and 273 K Neon at 2 atm and 73 K Neon at 1atm and 273 K Neon at 2 atm and 273 K
Helium in 1 atm + 273 K, neon at 1 atm, neon at 2 atm, neon at 2 atm, and neon at 73 K
Who or what uses neon?Advertising signs are the main application for neon gas. High voltage indicators are also made of neon, and helium-neon lasers are created by combining neon with helium. As a cryogenic refrigerant, liquid neon is employed.
What makes neon so scarce on Earth?Neon is extremely volatile and doesn't form any compounds that would allow it to be fixed to solids, which accounts for its relative paucity on Earth as well as the inner (terrestrial) planets. As a result, in the early Solar System, it broke free from the planetesimals while being warmed by the newly ignited Sun.
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Which of the following macromolecules is the most chemically stable, and can potentially survive in the rock record for millions or even billions of years? O Lipid RNA DNA Polysaccharide point Which of the following macromolecules can BOTH store information in sequence of nucleic acids AND potentially act as catalyst for biochemical reactions? Protein Polysaccharide Lipid DNA 0 RNA
1)Unlike other macromolecules, lipids can survive in rock records for millions or billions of years. This is typically used for rock quantification.
2)RNA is both a nucleotide acid and a prospective catalyst.
Macromolecules are largely polymers, which are long chains of molecular divisions known as monomers. Long polymers are found in carbohydrates, proteins, and nucleic acids. They are classified as macromolecules due to one‘s polymeric nature as well as large size. Macromolecules are massive molecules that populate cells and provide vital functions for life. Macromolecules, for example, offer structural support, a source of non - renewable power, the ability to store and collect genetic information, and the capacity to accelerate biochemical reactions. Lipids are fatty substances that serve numerous functions in your body. They are part of your cell membranes and help control what enters and exits your cells.
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If you had a closed jar with a fish and a plant in it, explain where photosynthesis and cellular respiration are each happening
Answer:
Photosynthesis would happen in the plant, while cellular respiration would happen in the plant and the fish. In the plant, photosynthesis occurs when light energy is converted into chemical energy used for growth and development. In fish, cellular respiration occurs when the fish takes in oxygen from the water and uses it to convert energy from food into usable energy...
Explanation:
which electrode is the anode, and which is the cathode? what are the signs of the electrodes? do electrons flow from the aluminum electrode to the nickel electrode, or from the nickel to the aluminum? in which directions do the cations and anions migrate through the solution? match the words in the left column to the appropriate blanks in the sentences on the right. resethelp alal nini blank electrode is the anode.target 1 of 8 blank electrode is the cathode.target 2 of 8 blank electrode is negative.target 3 of 8 blank electrode is positive.target 4 of 8 electrons flow from the blank electrode to the blank electrode.target 5 of 8target 6 of 8 anions migrate to the blank electrode.target 7 of 8 cations migrate to the blank electrode.target 8 of 8
Here, cathode seems to be the positive electrode and anode is the negative electrode. Positive (+) is the anode and negative (-) is the cathode. Thus, electrons go from the aluminosilicate and niobium
What does an electrode mean in electrical terms?A conductor used to establish contact with the a nonmetallic component of a circuit is known as an electrode. Electrodes are frequently employed in electrochemical cells, semiconductors including diodes, and medical equipment. The electrode is where the transport of electrons takes place.
What is the name of the two electrodes?Electrodes are divided into two categories, cathode and anode, depending on the sort of reaction that takes place in an electrochemical cell. Positive and negative charges, respectively, are present at the cathode and anode.
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Assign the oxidation state for nitrogen in each of the following. a. Li3N f. NO2 b. NH3 g. NO22 c. N2H4 h. NO32 d. NO i. N2 e. NO
Answer:
Here are the oxidation states for nitrogen in each of the compounds you listed:
a. Li3N - Nitrogen has an oxidation state of +3 in Li3N.
b. NH3 - Nitrogen has an oxidation state of -3 in NH3.
c. N2H4 - Nitrogen has an oxidation state of +1 in N2H4.
d. NO - Nitrogen has an oxidation state of +2 in NO.
e. NO - Nitrogen has an oxidation state of +2 in NO.
f. NO2 - Nitrogen has an oxidation state of +4 in NO2.
g. NO2 - Nitrogen has an oxidation state of +4 in NO2.
h. NO3 - Nitrogen has an oxidation state of +5 in NO3.
i. N2 - Nitrogen has an oxidation state of 0 in N2.
The oxidation state of an element is a measure of the degree of oxidation or reduction that has occurred in a compound. It is determined by the number of electrons that an element has gained or lost in forming a chemical bond.
Question:
Answer the following questions about the element selenium.
a) Samples of natural selenium contain six stable isotopes. In terms of atomic structure, explain what these isotopes have in common and how they differ.
b) Write the complete electron configuration (i.e. 1s2) for a selenium atom in the ground state. Indicate the number of unpaired electrons in the ground-state atom and how it may react in a chemical reaction. Explain your reasoning.
c) In terms of atomic structure, explain why the first ionization energy of selenium is less than that of bromine, and greater than that of tellurium.
d) Selenium reacts with fluorine to form selenium tetrafluoride. Draw the complete Lewis electron-dot structure for SeF4 and sketch the molecular structure. Indicate whether the molecule is polar or nonpolar, and justify your answer.
Selenium is a chemical element with the atomic number 34 and the symbol Se. It is a nonmetal with properties that are intermediate between sulphur and tellurium in the periodic table, as well as similarities to arsenic.
a) The isotopes have the same number (34) of protons, but a different number of neutrons.
b) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^4 is the complete electron configuration for a selenium atom.
c) Se' 1st ionization energy is greater than Te because Se is experiencing less shielding than Te, as a result Se' electrons are more attracted to the nucleus compared to Te.
d) Seesaw shape is the shape of the selenium tetrafluoride and the number of electrons is 34. It is polar due to Asymmetry.
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C=3×10(8)m/s, 1eV=1.6×10(-19)J , RH=1.079×10(7)m-1, 1nm=10(-9)m, 1A°=10(- 10)m, h=6.63×10(-34)J.s
The radioactivity A of a drop of iodine I-131 if the mass of the drop is 1.5 g and the period is 13h is:
The radioactivity A of a drop of iodine I-131 if the mass of the drop is 1.5 g and the period is 13h is: 1.29 x 10^(-11) disintegrations/second.
What is radioactivity?Generally, To find the radioactivity of a drop of iodine I-131, you will need to use the following formula:
A = (N/M) * ln(2) / T
where:
N is the number of atoms in the sampleM is the atomic mass of the isotopeln(2) is the natural logarithm of 2T is the half-life of the isotopeTo use this formula, you will need to know the atomic mass of I-131, which is about 130.906 amu, and its half-life, which is about 8.04 days. You will also need to convert the mass of the drop from grams to atomic mass units, which can be done by dividing the mass by the atomic mass of carbon-12 (12 amu).
First, convert the period from hours to seconds:
13 hours = 13 * 60 minutes/hour * 60 seconds/minute
= 5,040 seconds
Then, convert the period from seconds to days:
5,040 seconds = 5,040 seconds / (24 hours/day * 60 minutes/hour * 60 seconds/minute)
= 0.6 days
Then, calculate the half-life in seconds:
8.04 days = 8.04 days * 24 hours/day * 60 minutes/hour * 60 seconds/minute
= 691,840 seconds
Then, use the formula above to calculate the radioactivity:
A = (N/M) * ln(2) / T = (N/130.906 amu) * ln(2) / (691,840 seconds)
= (1.5 g / 12 amu) * ln(2) / (691,840 seconds)
= 0.125 * ln(2) / (691,840 seconds)
= 0.08867 * (1/691,840 seconds)
= 1.29 x 10^(-11) disintegrations/second
So the radioactivity of the drop of iodine I-131 is approximately 1.29 x 10^(-11) disintegrations/second.
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The energy change for an electronic transition in a one-electron atom or ion (H, He+, Li2+, etc.) from n initial to n final is given by delta E = -(2.18 times 10-18 J)(Z2)(1/n2 final - 1/n2 initial), where Z is the atomic number. Which one o f the following species will have the longest wavelength emission line for the transition between the n initial = 2 and n final = 1 levels? O H O He+ O Li2+ O Be3+
O B4+
H will have the longest wavelength emission line for the transition between the n initial = 2 and n final = 1 levels.
A movement (or leap) of an electron from one energy level to another within an atom or artificial atom is referred to as an atomic electron transition. It seems discontinuous because the electron "jumps" from one quantized energy level to another in a matter of nanoseconds or less.
Electronic transitions occur in atoms and molecules as a result of electromagnetic radiation absorption or emission (typically UV or visible). Planck's equation, E = h, relates the energy change associated with a transition to the frequency of an electromagnetic wave. Transitions between these permitted orbits occur in photon absorption or emission. A photon is released when an electron transitions from a higher-energy orbit to a more stable orbit.
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Consider the following exothermic reaction (with an enthalpy change of -514kJ) at equilibrium:
2 CO2 (g) <-----> 2 CO (g) + O2 (g)
Le Chatelier's principle states that the equilibrium partial pressure of CO(g) can be maximized by carrying out the reaction .
(a) at high temperature and high pressure
(b) at high temperature and low pressure
(c) at low temperature and low pressure
(d) at low temperature and high pressure
(e) none of the choices given here
The equilibrium partial pressure of CO(g) can be maximized by carrying out the reaction at low temperature and low pressure.
What does Le Chatelier's principle state?According to Le Chatelier's principle, when a dynamic equilibrium is disturbed by an external element, the equilibrium will move in a way that may counteract the effect of the external factor in order to maintain the equilibrium.
The given reaction is-
2CO₂(g) ⇄ 2CO(g) + O₂(g) (ΔH = -514 kJ)
Now, how does change in pressure and temperature affects the reaction-
Change in pressure:
The equilibrium will move toward the side where there are less moles of gas from the reaction as pressure rises. Additionally, when pressure drops, the equilibrium will move in favor of the side where there are more gas molecules involved in the process.
2.0 moles of gases are on the reactants side (on the left) and 3.0 moles are on the products side (on the right).
Therefore, lowering the pressure will cause the reaction to move to the side where there are more gas molecules (right side, products) and the equilibrium partial pressure of CO(g) can be maximized at low pressure.
Change in temperature:
The sign of H indicates that the reaction is exothermic (negative).
The concentration of the products side will decrease as the temperature drops, so the reaction will be moved to the right to counteract the temperature drop so that the equilibrium partial pressure of CO (g) can be maximized at low temperatures.
Hence the correct answer is low temperature and low pressure.
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Using the energy stated in the text for the process in equation (5.28), calculate the unified atomic mass unit (symbols: Da or u) of 13N.
The energy is -3.00 MeV and the reaction is p + 13C ----> 13N +n. Thank you
To calculate the unified atomic mass unit (u) of 13N using the energy of the reaction given in equation (5.28), you can use the following equation:
u = energy / c^2
where energy is the energy of the reaction in joules, c is the speed of light in meters per second, and u is the unified atomic mass unit in kilograms.
First, you need to convert the energy of the reaction from MeV (Mega electron volts) to joules. You can do this using the conversion factor of 1 MeV = 1.602 x 10^-13 joules. Plugging in the values for the energy of the reaction (-3.00 MeV) and the conversion factor, you get:
Energy in joules = -3.00 MeV * 1.602 x 10^-13 joules/MeV = -4.806 x 10^-13 joules
Next, you need to convert the speed of light from meters per second to joules per second. You can do this using the conversion factor of 1 m/s = 1 j/s. Plugging in the value for the speed of light (299,792,458 m/s) and the conversion factor, you get:
c = 299,792,458 m/s * 1 j/s = 299,792,458 j/s
Now you can plug in the values for energy and c into the equation above to calculate the unified atomic mass unit of 13N:
u = (-4.806 x 10^-13 joules) / (299,792,458 j/s)^2 = 1.50 x 10^-27 kilograms
This is the unified atomic mass unit of 13N in kilograms. You can convert this value to atomic mass units (amu) by dividing it by 1.660 x 10^-27 kilograms/amu:
u in amu = 1.50 x 10^-27 kilograms / (1.660 x 10^-27 kilograms/amu) = 0.906 amu
Therefore, the unified atomic mass unit (u) of 13N is approximately 0.906 amu.
Which of the following accurately describes minerals? A) When a food is burned, all the minerals are found in the ash. B) The body absorbs each mineral from foods in much the same way. C) Minerals in food can be destroyed by acid. D) The body needs about 200 milligrams of each trace mineral each day. E) Major minerals are more important than trace minerals.
When a food is burned, all the minerals are found in the ash. Therefore, the correct option is option A which accurately describes minerals among all the given options.
What is mineral?A mineral is unique from its synthetic analogues, which must be generated through natural processes by definition. Artificial minerals, such as emeralds, diamond, sapphires, and other expensive gemstones, are routinely made in industry and scientific facilities and are frequently almost similar to their biological counterparts.
There are thousands of known mineral species, with around 100 of them constituting the primary dissolved minerals of rocks; they are known as rock-forming minerals. When a food is burned, all the minerals are found in the ash.
Therefore, the correct option is option A.
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Another sample of eggshell reacts completely with 4.0 mL of an HCl(aq) solution of unknown concentration. If the reaction produced 0.095 atm of gas, the concentration of the HCl(aq) solution was at least (A) 0.0020 M (B) 0.050 M (C) 0.50 M (D) 1.0M
The concentration of the HCl (aq) solution was at least 1.0 M.
What is concentration?The abundance of a constituent divided by the sum of the mixture's volumes is the definition of concentration in chemistry. There are several different categories of mathematical description: mass concentration, molar concentration, number concentration, and volume concentration
P = 0.095atm(corresponds to 0.20g of CaCO3
so,moles of CaCO3 =0.20g/100gmol⁻¹=0.002moles
moles of HCl =(molesₓCaCO3ₓ2)=0.002ₓ2
M=0.004/4ₓ100
Concentration of HCl=1M
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what is the name of (CH3CH2)2COHCH3
The name of the compound (CH3CH2)2COHCH3 is butane-2,3-diol.
The compound is an alcohol, which means it contains a hydroxyl (-OH) group. The prefix "butane-" indicates that it has four carbon atoms in a straight chain, and the suffix "-diol" indicates that it contains two hydroxyl groups. The prefix "2,3-" specifies the positions of the hydroxyl groups on the carbon chain.
Butane-2,3-diol is also known by other names, including 2,3-butanediol, 2,3-dihydroxybutane, and 1,4-butanediol. It is a colorless, viscous liquid that is used in the production of plastics, solvents, and other chemicals.
The name of (CH3CH2)2COHCH3 compound is butane- 2,3- diol.
What is butane- 2,3- diol ?The organic substance 2,3-butanediol has the formula (CH3CHOH)2. It falls under the vic-diol category. It exists as a chiral pair, three stereoisomers, and a meso isomer. All liquids are colorless. Precursors for various polymers and insecticides are examples of applications.
A butanediol with hydroxylation at C-2 and C-3 is known as butane-2,3-diol. It is a secondary alcohol, a glycol, and a butanediol.
Among its many possible uses are the production of printing inks, perfumes, synthetic rubber, fumigants, antifreeze agents, fuel additives, foodstuffs, and pharmaceuticals. 2,3-Butanediol (2,3-BD) is a promising bulk chemical.
Alcohols classified as primary have just one alkyl group on which the carbon atom of the hydroxyl group (OH) is connected. These major alcohols include, for instance, ethanol, methanol (propanol),
Thus, The name of (CH3CH2)2COHCH3 compound is butane- 2,3- diol.
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Carlos rides his bike away from the school at a constant speed. Explain what a
distance-time graph for this type of motion
would look like.
The slope of a distance-time graph for this motion will have a straight line to represent that the object in motion is at a constant speed.
What is a distance-time graph?A distance-time graph depicts how far an object has traveled in a specified amount of time. It is a simple line graph that depicts distance versus time findings. The Y-axis represents distance. On the X-axis, time is plotted.
The slope of the distance-time graph should always be constant because the bike is moving at a constant speed. As a result, the graph will be a straight line through the origin.
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Mitochondrial conditions determine the degree of reduction of each carrier in the respiratory chain. For example, when NADH and , are abundant, tlu steady-state degree of reduction of the carriers decreases as electrons pass from the substrate too, When electron transfer is blocked, the carriers before the block become more reduced and those beyond the block become more oxidined. Match the state of oxidation for ubiquinone (C) and cytochrome, 1.6,4, and as with each mitochondrial condition. Abundant NADH and Oy, but cyanide added only canken under de los contented. Abundant NADH, but o, exhausted All wien werden All card Abundant o, but NADH exhausted Biarly care dorproduto ou come mai bine Abundant NADH and O2
All transporters were reduced as cytochrome oxidation is inhibited by cyanide. Since there is no terminating electron acceptor when O2 is absent, all carriers undergo reduction.
Who or what is an electron?A negative charges particle known as an electron can be either independent or attached to an atom (not bound). Another of the three main types of elements within an atom is an electrode that is bonded to it; the other couple are protons & neutrons.
What gives electrons their energy?An electron's energy is determined by where it is in relation to the atom's nucleus. The distance an electron inside an atom has to travel from the nucleus depends on its energy level.
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The energy of a photon of green light is 3.74x10^–19 J and the energy of a photon of infrared radiation is 9.25x10^–20 J. Green light has a ______________ frequency and a ________________ wavelength than infrared radiation.
A. higher, shorter
B. higher, longer
C. lower, shorter
D. lower, longer
Explain your answer.
Green light has a higher frequency and shorter wavelengths than infrared radiation. Option A is correct.
What is the difference between green light and infrared radiation?On the electromagnetic spectrum, green light, which is visible light, has a wavelength that falls between 380 nm and 750 nm, while infrared light, which begins at 700 nm and extends to 1 mm, is just beyond it. Because of this, infrared can only be viewed with specialised tools like security cameras.
Due to their longer wavelengths than visible light, infrared waves can travel across crowded areas of gas and dust in space without being significantly scattered or absorbed. In comparison to infrared photons, visible light has shorter wavelengths and higher frequency.
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