# Question f51ce

Sep 11, 2017

At STP, the volume of chlorine used is 90.9 L.

#### Explanation:

There are four steps involved in this stoichiometry problem:

Step 1. Write the balanced chemical equation.

${M}_{r} : \textcolor{w h i t e}{m m m m m m m} 36.46$
$\textcolor{w h i t e}{m m m} \text{H"_2 + "Cl"_2 → "2HCl}$

2. Convert grams of $\text{HCl}$ to moles of $\text{HCl}$

$\text{Moles of HCl" = 292 color(red)(cancel(color(black)("g HCl"))) × ("1 mol HCl")/(36.46 color(red)(cancel(color(black)("g HCl")))) = "8.009 mol HCl}$

Step 3. Convert moles of $\text{HCl}$ to moles of ${\text{Cl}}_{2}$

${\text{Moles of Cl"_2 = 8.009color(red)(cancel(color(black)("mol HCl"))) × ("1 mol Cl"_2)/(2 color(red)(cancel(color(black)("mol HCl")))) = "4.004 mol Cl}}_{2}$

4. Calculate the volume of ${\text{Cl}}_{2}$

At STP (1 bar and 0 °C), the molar volume of a gas is 22.71 L.

V = 4.004 color(red)(cancel(color(black)("mol"))) × "22.71 L"/(1 color(red)(cancel(color(black)("mol")))) = "90.9 L"#

The volume of ${\text{Cl}}_{2}$ used is 90.9 L.

Here's a useful video on mass-volume conversions.