How many moles of water can be made from 4 moles of oxygen gas and 16 moles of hydrogen gas?

Question

also, what is the limiting reagent?

Answer 1

The chemical reaction between Hydrogen gas (H2) and Oxygen gas (O2) is as follows,

2 H2 (g) + O2 (g) --> 2 H2O (g)
2 moles of Hydrogen gas plus 1 mole of Oxygen gas, reaction to form 2 mole of water.

For every 1 mole of Oxygen gas reacted, 2 moles of Hydrogen gas are required.
In your problem, you have 4 moles of Oxygen gas, so 4 * 2 = 8 moles of Hydrogen gas are required. The problem says that 16 moles of Hydrogen gas are available, so you have twice as much Hydrogen gas than is necessary. Oxygen gas in thus your limiting reagent and Hydrogen gas is in excess.

For every 1 mole of Oxygen gas which reacts will help for 2 moles of water.
Since all 4 moles of Oxygen gas will react, 2 * 4 = 8 moles of water will be formed due to this reaction.

In the end, there will be 8 moles of water formed and 8 moles of H2 left over. There will be no Oxygen gas left in the end.

Answer 2

4 moles.............oxygen is the limiting reagent.

water has 1 O and 2 H. there are 4 times as many H as there are O so that makes O the limiting reagent. Also, since there is one O atom in water, the moles of water will equal the moles of oxygen.

Answer 3

only four, the chemical formula for water is H2O, meaning two mole's hydrogen combined with one mole of oxygen.
you will have eight moles of hydrogen left over

Answer 4

8 H2 + 4 O2 ==> 8 H2O + 8H2