Question

${PCl}_3\left(g\right)+{Cl}_2\left(g\right)\rightleftharpoons {PCl}_5\left(g\right)+energy$
When the reaction shown above is in equilibrium, which statement is true?

• A. The temperature will be increasing.
• B. The temperature will be decreasing.
• C. The amount of $P{Cl}_3$ will be increasing.
• D. The amount of $P{Cl}_5$ will be increasing.
• E. ${Cl}_2$ will be formed and used at equal rates.

Answer 1

The correct option is E ${Cl}_2$ will be formed and used at equal rates.

The given reaction is :-

${PCl}_3\left(g\right)+{Cl}_2\left(g\right)\rightleftharpoons {PCl}_5\left(g\right)+energy$

When the reaction is at equilibrium then rates of forward and backward reactants are equal. So, consumption of reactants and their formation occurs at equal rates. So, ${Cl}_2$ will be formed & used at equal rates.