# Question fcb1b

Jun 23, 2016

$\text{1 L}$

#### Explanation:

The idea here is that when kept under constant pressure and temperature, the volume of gas is directly proportional to how many moles of gas it contains $\to$ this is known as Avogadro's Law.

This means that for a chemical reaction that involves gases kept under the same conditions for pressure and temperature, the mole ratios given by the stoichiometric coefficients become equivalent to volume ratios.

$\textcolor{b l u e}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} {n}_{1} / {n}_{2} = {V}_{1} / {V}_{2} \textcolor{w h i t e}{\frac{a}{a}} |}}} \to$ the mole ratio is equivalent to a volume ratio

So, the balanced chemical equation that describes the formation of hydrogen chloride from hydrogen gas and chlorine gas looks like this

${\text{H"_ (2(g)) + "Cl"_ (2(g)) -> color(red)(2)"HCl}}_{\left(g\right)}$

Notice that $1$ mole of hydrogen gas needs $1$ mole of chlorine gas to produce $\textcolor{red}{2}$ moles of hydrogen chloride.

Since all the gases are kept under the same conditions for pressure and temperature, this is equivalent to saying that $\text{1 L}$ of hydrogen gas needs $\text{1 L}$ of chlorine gas to produce $\textcolor{red}{2} \textcolor{w h i t e}{a} \text{L}$ of hydrogen chloride.

Since you must produce $\text{2 L}$ of hydrogen chloride, it follows that you must consume $\text{1 L}$ of chlorine gas, provided of course that you also have $\text{1 L}$ of hydrogen gas available for the reaction.

"volume of Cl"_(2(g)) = color(green)(|bar(ul(color(white)(a/a)color(black)("1 L")color(white)(a/a)|)))#