Question

2H2S + 3O2 --> 2SO2 + 2H2O How many grams of oxygen are required to react with 2.30g g dihydrogen sulfide?

Answer 1

Here's what you need to do:
1.) Find the molecular weight of dihydrogen sulfide, and convert the sample mass to mols.
2.) Figure out for a given amount of mols of dihydrogen sulfide, how many mols of oxygen are required to carry out the reaction. Since its a ratio of 2 to 3, this means for every 2 mols of H2S you need 3 mols of O2. Setup a proportion fraction to find this.
3.) Find the molecular weight for O2 (oxygen gas), and convert the mols you obtained from step 2 to grams.

Hope this helps!