Question

Consider the following reaction:

2Na+2HCl→2NaCl+H2

How many mols of hydrogen gas (H2) can be produced if you begin with 24.95 grams of each reactant?

Answer 1

Number of moles of Na = 24.95 g / 22.9897 g/mol = 1.09 mole

Number of moles of HCl = 24.95 g / 36.46 g/mol = 0.684 mole

From the balanced equation we can say that

2 mole of Na requires 2 mole of HCl so

1.09 mole of Na will require

= 1.09 mole of Na *(2 mole of HCl / 2 mole of Na)

= 1.09 mole of HCl

But we have 0.684 mole of HCl which is in short so HCl is limiting reactant

From the balanced equation we can say that

2 mole of HCl produces 1 mole of H2 so

0.684 mole of HCl will produce

= 0.684 mole of HCl *(1 mole of H2 / 2 mole of HCl)

= 0.342 mole of H2

Therefore, the number of moles of H2 produced would be 0.342