Question

If 3.0 moles H2S and 1.0 mole SO2 react according to the following equation, how many moles of water will form? Reaction: 2H2S + SO2 → 3S + 2H2O

Answer 1

Answer:  2 moles of $H_2O$ will be formed.

Explanation: Reaction in the given question is :

$2H_2S+SO_2\rightarrow 3S+2H_2O$

Number of moles of $SO_2$ = 1 mole

Number of moles of $H_2S$ = 3 moles

Here, the excess reagent is $H_2S$ because its number of moles are more and $SO_2$ is the limiting reagent as its number of moles are less.

So, the amount of $H_2O$ produced will depend on the the amount of $SO_2$ used.

By stoichiometry, one molecule of $SO_2$ produces 2 molecules of $H_2O$.

Therefore, 1 mole of $SO_2$ will produce 2 moles of $H_2O$.