Answer:
It is a decomposition reaction.
Always start with the balanced equation:
2H2 + O2 ==> 2H2O ... balanced equation
Anytime you are given amounts of BOTH reactants, you MUST find the limiting reactant:
10.9 g H2 x 1 mol H2/2 g H2 = 5.45 mol H2
16.03 g O2 x 1 mol O2/32 g O2 = 0.500 mol O2
Clearly, by looking at the balanced equation you can tell that O2 is limiting because it takes 2 mol H2 for each 1 mol O2, and there is plenty of H2 present (5.45 mol vs. 0.500 mol).
Now you can find maximum amount H2O formed:
0.500 mol O2 x 2 mol H2O / 1 mol O2 x 18 g H2O/mol H2O = answer in grams
2 H2 + O2 → 2 H2O, you get the same number of moles of water as H2, as long as you have 1 mole of O2. So, with 3 moles of H2, as long as you have 1.5 moles of O2, you will get 3 moles of H2O.
The equation shows that: 2 moles of H2 react with 1 mole of O2 in this equation (that is what the numbers in front of the formulae mean) and produce 2 moles of water.
2 H2 + O2=====> 2 H2O
So 2- moles of Hydrogen reacts with 1- mole of Oxygen to form 2- moles of water.
Therefore 3- moles of hydrogen will react with 1.5- moles of Oxygen to form 3- moles of water.
Here hydrogen is the LIMITING AGENT. OXYGEN is present in EXCESS AMOUNT.
1 mole of H2O = 18 g (molar mass of H2O)
Hope this helps, please let me know if it wrong.
