# Question #0fbb3

Jun 5, 2017

You need 20 L of hydrogen to produce 20 L of steam.

#### Explanation:

We can use Gay-Lussac's Law of Combining Volumes to solve this problem.

Step 1. Write the chemical equation.

$\text{2H"_2"(g)" + "O"_2"(g)" → "2H"_2"O} \left(g\right)$
$\textcolor{w h i t e}{l l} \text{2 L"color(white)(mmmmmmmml)"2 L}$

According to Gay-Lussac's Law, 2 L of hydrogen produce 2 L of steam.

Step 2. Calculate the volume of hydrogen

${\text{Volume of H"_2 = 20 color(red)(cancel(color(black)("L H"_2"O"))) × "2 L H"_2/(2 color(red)(cancel(color(black)("L H"_2"O")))) = "20 L H}}_{2}$