PL HELP M
2 Li + H2SO4 → Li2SO4 + H2
If 1.5107 moles of Li are reacted with 0.0745 moles of H2SO4, how many moles of H2 will be produced?

0.0745 mole of hydrogen gas

Explanation:

Given parameters:

Number of H₂SO₄ = 0.0745 moles

Number of moles of Li = 1.5107 moles

Unknown:

Number of moles of H₂ produced = ?

Solution:

To solve this problem, we have to work from the known specie to the unknown one.

The known specie in this expression is the sulfuric acid,  H₂SO₄. We can compare its number of moles with that of the unknown using a balanced chemical equation.

   Balanced chemical equation:

                    2Li   +     H₂SO₄   →   Li₂SO₄   +   H₂

 From the balanced equation;

Before proceeding, we need to obtain the limiting reagent. This is the reagent whose given proportion is in short supply. It determines the extent of the reaction.

           2 mole of Li reacted with 1 mole of  H₂SO₄

          1.5107 mole of lithium will react with  = 0.7554mole of H₂SO₄

But we were given 0.0745 moles,

This suggests that the limiting reagent is the sulfuric acid because it is in short supply;

   since 1 mole of sulfuric acid produced 1 mole of hydrogen gas;

    0.0745 mole of sulfuric acid will produce 0.0745 mole of hydrogen gas