Question

Question #5aa17

Answer 1

The chemical reaction is based from the number of moles of each species participating in the reaction and not by its volume.

Explanation:

This is how it works:

First, this is the reaction for the formation of water:
`H_2 + 1/2 O_2 rarr H_2O`

All chemical reactions are based on the number of moles (see those coefficients?) and not in their volume. Meaning 1 mole of `H_2`(hydrogen gas) will react with a half mole of `O_2`(oxygen gas) to form 1 mole of liquid water.

Answer 2

The answer lies in Avogadro's Hypothesis.

Explanation:

Avogadro's Hypothesis states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.

The chemical equation for the formation of water is

`"2H"_2"(g)" + "O"_2"(g)" → 2"H"_2"O(g)"`

We could also write

`"2 mL + 1 mL → 2 mL"`

or

`"100 mL + 50 mL → 100 mL"`

The volumes will always be in the same `2:1:2` ratio as the coefficients in the balanced chemical equation.