Question

At elevated temperatures, molecular hydrogen and molecular bromine react to partially form hydrogen bromide:

Answer 1

Answer: The moles of bromine gas at equilibrium is 0.324 moles.

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$        .......(1)

Calculating the initial moles of hydrogen and bromine gas:

• For hydrogen gas:

Moles of hydrogen gas = 0.682 mol

Volume of solution = 2.00 L

Putting values in equation 1, we get:

$\text{Molarity of solution}=\frac{0.682mol}{2.00L}=0.341M$

• For bromine gas:

Moles of bromine gas = 0.440 mol

Volume of solution = 2.00 L

Putting values in equation 1, we get:

$\text{Molarity of solution}=\frac{0.440mol}{2.00L}=0.220M$

Now, calculating the molarity of hydrogen gas at equilibrium by using equation 1:

Equilibrium moles of hydrogen gas = 0.566 mol

Volume of solution = 2.00 L

Putting values in equation 1, we get:

$\text{Molarity of solution}=\frac{0.566mol}{2.00L}=0.283M$

Change in concentration of hydrogen gas = 0.341 - 0.283 = 0.058 M

This change will be same for bromine gas.

Equilibrium concentration of bromine gas = $(\text{Initial concentration}-\text{Change in concentration})=0.220-0.058=0.162M$

Now, calculating the moles of bromine gas at equilibrium by using equation 1:

Molarity of bromine gas = 0.162 M

Volume of solution = 2.00 L

Putting values in equation 1, we get:

$0.162M=\frac{\text{Moles of bromine gas}}{2.00L}\\\\\text{Moles of bromine gas}=(0.162mol/L\times 2.00L)=0.324mol$

Hence, the moles of bromine gas at equilibrium is 0.324 moles.