A solution of nitric acid has a [H3O+] = 2.8 x 10-6 M. What is the pH?

Answer: last one is right

Explanation: atoms of same element have always same number of protons but may have several isotopes which have different number of neutrons.

Answer:

pH = 2.88

Explanation:

For a weak acid solution, the pH can be calculated using the following formulas:

Where Ka = [tex]10^{-pKa}[/tex] and C is the molar concentration.

We are given Ka and C by the problem, meaning we can now proceed to calculate [H⁺]:

Finally we calculate the pH:

Answer:

The sample of __Ca___ contains the greatest number of atoms

Explanation:

As we know,

1 mole [tex]= 6.022*10^{23}[/tex] molecular entities (Can be atom, ions or molecules)

Number of atoms in 1.76 mole sample of Be

[tex]= 6.022*10^{23} *1.76\\= 1.059 * 10^{24}[/tex]

The sample of __Ca___ contains the greatest number of atoms

Answer:

0 587 mL

Explanation:

First we convert 180 grams of HCl into moles, using its molar mass:

Now we can use the number of moles and the given concentration to calculate the required volume, applying the definition of molarity:

Finally we convert liters into milliliters:

The closest answer is option C, 587 mL.

The volume needed to make an 8.40 M solution of HCl is 0.587 ml.

The correct option is C.

HCl is a strong acid. It is present in our stomach to help in digesting food.

Step1: covert 180 grams into moles

Molar mass of HCl is 36.46 g

[tex]\dfrac{180 g}{36.46 g/mol } = 4.94\; mol\; HCl[/tex]

Step2: calculate the molarity

[tex]\rm Molality = \dfrac{mol}{L}\\\\\rm L = \dfrac{4.94 mol }{8.40 M} = 0.588 L\\[/tex]

Covert the liters into ml

[tex]\dfrac{0.588 L}{1000} = 588 mL[/tex]

Thus, the volume of the solution is 588 ml., nearest is option C, 587 ml.

Learn more about HCl

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As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.

Answer:

As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.

Answer:

2 L

Explanation:

From the question

Applying boyles law,

PV = P'V'....................... Equation 1

Where P = Initial pressure, P' = Final Pressure, V = Initial Volume, V' = Final Volume.

make V' the subject of the equation

V' = PV/P'.................... Equation 2

Givne: V = 5 L, P = 500 mmHg, P' = 1240 mmHg

Substitute these values into equation 2

V' = (5×500)/1240

V' = 2500/1240

V' = 2 L

Answer:

166.11 mol

Explanation:

I hope you mean molecules

1 mol of anything is 6.02 * 10^23

x mol of anything is 1 * 10^26

1/x = 6.02 * 10^23/1 * 10^26              Cross multiply

1 * 1*10^26 = 6.02*10^23 * x              Divide by 6.02*10^23

1*10^26/6.02 * 10^23 = x

x = 166.11 mol

Answer:

THE ANSWER IS 1.167L

Explanation:

Answer: 1672 Joules

Explanation:

The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

[tex]Q=m\times c\times \Delta T[/tex]

Q = Heat absorbed by water = ?  

c = heat capacity of water = [tex]4.18 J/g^0C[/tex]

Initial temperature of the water = [tex]T_i[/tex] = [tex]27^0C[/tex]

Final temperature of the water  = [tex]T_f[/tex]  = [tex]35^0C[/tex]

Change in temperature ,[tex]\Delta T=T_f-T_i=(35.0-27.0)^0C=8.0^0C[/tex]

Putting in the values, we get:

[tex]Q=50.0g\times 4.18J/g^0C\times 8.0^0C=1672J[/tex]

As heat absorbed by water is equal to the heat released by metal, the Joules of heat transferred are 1672 Joules

Answer:

That one is tricky but i would say yellow

Explanation:

Answer:

nitrogen oxide

Explanation:

Answer:

A chemical bond holds atoms together.

Answer:

D - synapse

Explanation:

Synapse, also called neuronal junction, the site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector). A synaptic connection between a neuron and a muscle cell is called a neuromuscular junction.

Answer:

Aà bhûtÿ ñhjkjłfd hÿrèërqw

Explanation:

Explanation:

make me brainy least pkz

Answer:

160 mol H₂O

Explanation:

Step 1: Write the balanced complete combustion reaction

CH₄ + 2 O₂ ⇒ CO₂ + 2 H₂O

Step 2: Establish the appropriate molar ratio

According to the balanced equation, the molar ratio of CH₄ to H₂O is 1:2.

Step 3: Calculate the moles of water formed from 80 moles of methane

We will use the previously established molar ratio.

80 mol CH₄ × 2 mol H₂O/1 mol CH₄ = 160 mol H₂O

Answer:

C.

Explanation:

Answer:

The right approach is "50 g/l".

Explanation:

The given values are:

Mass or solute or precipitation,

= 0.15 kg

on converting it into "g", we get

= [tex]0.15 \ kg\times \frac{1000 \ g}{1 \ kg}[/tex]

= [tex]150 \ g[/tex]

Volume of solution,

=  3.00 L

Now,

The solubility of X will be:

=  [tex]\frac{Mass \ of \ X}{Volume \ of \ solution}[/tex]

On substituting the values, we get

=  [tex]\frac{150}{3}[/tex]

=  [tex]50 \ g /l[/tex]

Answer:

1.24 L

Explanation:

Avogadro's Law

[tex]\frac{V_{1} }{n_{1} } = \frac{V_{2} }{n_{2} }[/tex]

Convert 0.590 g of He to moles.

0.590 g x (1 mol/4.00 g) = 0.1475 mol He

Add 0.1475 mol to 0.100 mol since the initial moles (n1) increases by this amount.

0.100 mol + 0.1475 mol = 0.2475 mol He

This will represent the final moles (n2)

The initial volume is given, 0.500 L. Plug in the values.

[tex]\frac{0.500 L}{0.100 mol} = \frac{V_{2} }{0.2465 mol}[/tex]

[tex]V_{2} = \frac{(0.500 L)(0.2475 mol)}{(0.100 mol)} \\V_{2} = 1.2375\\V_{2} = 1.24 L[/tex]

Taking into account the Avogadro's law, the new volume will be 1.24 L.

Avogadro's law establishes the relationship between the amount of gas and its volume when the temperature and pressure are held constant. Remember that the amount of gas is measured in moles.

This law states that constant pressure and temperature, the same amount of gas has the same volume regardless of the chemical element that forms it.

On the other hand, Avogadro's law establishes that the volume is directly proportional to the quantity of gas: if the quantity of gas increases, the volume will increase; whereas if the amount of gas decreases, the volume decreases.

Mathematically, this law states that the ratio between the volume and the quantity of gas is constant:

[tex]\frac{V}{n} =k[/tex]

Assuming that you have an initial state 1 and the conditions are modified to a final state 2, it is true:

[tex]\frac{V1}{n1} =\frac{V2}{n2}[/tex]

In this case, being the molar mass of He 4 g/mole, 0.590 grams of He are contained in the following amount of moles:

[tex]0.590 gramsx\frac{1 mole}{4 grams} =0.1475 moles[/tex]

Then, you know:

Replacing in Avogadro's Law:

[tex]\frac{0.500 L}{0.100 moles} =\frac{V2}{0.2475 moles}[/tex]

Solving:

[tex]V2=0.2475 molesx\frac{0.500 L}{0.100 moles}[/tex]

V2= 1.2375 L≅ 1.24 L

Finally, the new volume will be 1.24 L.

Learn more:

Explanation:

it has different temperature but uniform humidity

hope it will help you

Answer:0.034%

Explanation:

Answer:

Average atomic mass = 32.057 u

Explanation:

Average atomic mass = Σ(isotope × abundance)

Average atomic mass = (0.95 × 31.972) + (0.0076 × 32.971) + (0.0422 × 33.967)

Average atomic mass = 32.057 u

Answer:

20.2 amu.

Explanation:

Let A represent isotope ²⁰X

Let B represent isotope ²²X

From the question given above, the following data were obtained:

For Isotope A (²⁰X):

Mass of A = 20

Abundance (A%) = 90%

For Isotope B (²²X):

Mass of B = 22

Abundance (A%) = 10%

Relative atomic mass (RAM) =?

The relative atomic mass (RAM) of the element can be obtained as follow:

RAM = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]

RAM = [(20 × 90)/100] + [(22 × 10)/100]

RAM = 18 + 2.2

RAM = 20.2 amu

Thus, relative atomic mass (RAM) of the element is 20.2 amu

Answer:

B.

Explanation:

it's B because 4 x 2 is 8 and we all know 8 x 8 is 64. So the answer is B.

The equation that is correct if the volume of a block is 64 cm³ is 8 cm x 4 cm x 2 cm = 64 cm³. The correct option is B.

Volume is the space occupied by any three-dimensional object. The volume is also considered as the total weight of the object. The volume is calculated as mass is divided by the density.

A block will be a rectangle because it contains length, breadth, and height. The formula will be V = L x B x H

As take all the options, and multiply them, we can calculate the actual volume of the box;

5 cm x 5 cm x 5 cm = 125

8 cm x 4 cm x 2 cm = 64 cm3

5 cm + 5 cm + 5 cm = 15

8 cm + 4 cm + 2 cm = 14

So, the correct option will be B, 8 cm x 4 cm x 2 cm = 64 cm. All others are incorrect.

Thus, the correct option is B.  8 cm x 4 cm x 2 cm = 64 cm.

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I haven't done these in some time, so I'm not sure if they are 100% right.

1) 6.3 moles of H2( 2 mol of NH3 / 3  mol of H2)= 4.2 mol of NH3

6.3 moles of H2( 2 mol of NH3/ 3 mol of H2)(17.04 g of NH3/1 mol NH3)= 71.57 g of NH3

2) 2.5 moles of N2(2 mol of NH3/1 mol of N2)= 5 moles of NH3

2.25 moles of N2(2 mol of NH3/ 1 mol of N2)(6.02x10^23 particles/ 1 mol of NH3)= 3.01x10^24 particles of NH3

3) 425 g of NH3(1 mol of NH3/17.04 g NH3)= 24.9 moles of NH3

425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)(28.02 g of N2/1 mol N2)= 349 g of N2

425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)= 12.5 mol of N2

4) 10 moles NH3(3 moles of H2/2 moles of NH3)= 15 moles H2

10 moles NH3(3 mol of H2/2 mol of NH3)(2.02 g of H2/1 mol of H2)= 30.3 g of H2

30.3 g = .0303 liters of H2

Answer:

B: Covalent bond and Ionic bond