Question

Use the equation below to determine the limiting reactant.

2 Li + H2SO4 --> H2 + Li2SO4
When 3 moles of Li are reacted with 3 moles of H2SO4, what is the limiting reactant and why?

H2SO4 because it has a higher molar mass than Li


Li because you will run out of Li first


Neither -- you have the same number of moles of both reactants


H2SO4 because you will run out of H2SO4 first

Answer 1

To determine the limiting reactant, we need to compare the number of moles of each reactant to the stoichiometric coefficients in the balanced equation.

The balanced equation tells us that 2 moles of Li react with 1 mole of H2SO4. Therefore, if we have 3 moles of Li and 3 moles of H2SO4, we can see that we have an excess of H2SO4 because we only need 1.5 moles of H2SO4 to react with all 3 moles of Li.

So the limiting reactant is Li because it will run out first. We have 1.5 moles of H2SO4 left over after the reaction is complete.

Therefore, the correct answer is:

Li because you will run out of Li first.