Answer:
8.34
Explanation:
1) how much moles of NH₃ are in the reaction;
2) how much moles of H₂ are in the reaction;
3) the required mass of the H₂.
all the details are in the attachment; the answer is marked with red colour.
Note1: M(NH₃) - molar mass of the NH₃, constant; M(H₂) - the molar mass of the H₂, constant; ν(NH₃) - quantity of NH₃; ν(H₂) - quantity of H₂.
Note2: the suggested solution is not the shortest one.
All atoms of the same element have the same
number of protons. Every atom also has a nucleus.
Molarity = moles of solute/volume of solution in liters.
From this relation, we can figure out the number of moles of solute by multiplying the molarity of the solution by the volume in liters.
We have 53.1 mL, or 0.0531 L, of a 12.5 M, or 12.5 mol/L, solution. Multiplying 12.5 mol/L by 0.0531 L, we obtain 0.664 moles. So, in this volume of solution, there are 0.664 moles of solute (HCl).
Answer:

Explanation:
If we want to convert from grams to moles, the molar mass is used. This is the mass of 1 mole. They are found on the Periodic Table as the atomic masses, but the units are grams per mole (g/mol) instead of atomic mass units (amu).
Look up the molar mass of carbon.
Set up a ratio using the molar mass.

Since we are converting 3.06 grams to moles, we multiply by that value.

Flip the ratio. This way, the ratio is still equivalent, but the units of grams of carbon cancel.

The original measurement of grams (3.06) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.
The 7 in the ten-thousandth place tells us to round the 4 up to a 5.

3.06 grams of carbon is approximately <u>0.255 moles of carbon.</u>
Answer:
<em>The number of electrons transferred in the reaction</em>
Explanation: