In the reaction PCl3 + Cl2 → PCl5, what is the mole ratio of PCl3 to PCl5?

• A. 2:1
• B. 1:1
• C. 2:2
• D. 1:2

Answer: (B)

Verified step by step guidance

1. Write the balanced chemical equation for the reaction: \(\mathrm{PCl_3 + Cl_2 \rightarrow PCl_5}\).
2. Identify the coefficients of each compound in the balanced equation. Here, the coefficient for \(\mathrm{PCl_3}\) is 1 and for \(\mathrm{PCl_5}\) is also 1.
3. Understand that the mole ratio between reactants and products is given by their coefficients in the balanced equation.
4. Therefore, the mole ratio of \(\mathrm{PCl_3}\) to \(\mathrm{PCl_5}\) is \$1:1$.
5. This means that 1 mole of \(\mathrm{PCl_3}\) reacts to form 1 mole of \(\mathrm{PCl_5}\).