For the reaction 2A ⇌ B + C, if the initial concentration of A is 0.5 M and at equilibrium, [B] = 0.2 M, what is the equilibrium concentration of A?
Practice Questions
1 question
Q1
For the reaction 2A ⇌ B + C, if the initial concentration of A is 0.5 M and at equilibrium, [B] = 0.2 M, what is the equilibrium concentration of A?
0.1 M
0.2 M
0.3 M
0.4 M
At equilibrium, 0.5 - 0.2 = 0.3 M of A remains.
Questions & Step-by-step Solutions
1 item
Q
Q: For the reaction 2A ⇌ B + C, if the initial concentration of A is 0.5 M and at equilibrium, [B] = 0.2 M, what is the equilibrium concentration of A?
Solution: At equilibrium, 0.5 - 0.2 = 0.3 M of A remains.
Steps: 6
Step 1: Write down the initial concentration of A, which is 0.5 M.
Step 2: Identify the change in concentration of A when the reaction reaches equilibrium. Since 2 moles of A produce 1 mole of B, for every 1 mole of B formed, 2 moles of A are consumed.
Step 3: At equilibrium, we know that the concentration of B is 0.2 M. This means that 0.2 M of B was formed from A.
Step 4: Calculate how much A was consumed to form 0.2 M of B. Since 2 moles of A are needed to produce 1 mole of B, we use the ratio: 0.2 M B x 2 = 0.4 M A consumed.
Step 5: Subtract the amount of A consumed from the initial concentration of A: 0.5 M (initial A) - 0.4 M (A consumed) = 0.1 M of A remains.
Step 6: Therefore, the equilibrium concentration of A is 0.1 M.
