Algebra and Reaction Rates

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Date:

📚 Part 1: Multiple Choice & Matching

1. Which algebraic equation shows a reaction rate directly proportional to concentration of A?

rate = k[A]

rate = k[A]^2

rate = k/[A]

rate = k

2. If doubling the concentration of A causes the reaction rate to double, which statement is correct?

The rate is proportional to [A]^2

The rate is proportional to [A]^1

The rate is independent of [A]

The rate is proportional to 1/[A]

3. Match each algebraic rate expression (left) with the best real-world description (right). Draw lines between matching items.

A. rate = k[A]

B. rate = k[A]^2

C. rate = k (constant)

D. rate = Δ[A]/Δt

1. Measured average change in concentration per second

2. Rate increases by four times when [A] doubles

3. Rate depends linearly on [A] (e.g. doubling [A] doubles rate)

4. Reaction rate is constant regardless of [A] (e.g. catalyst-limited)

✏️ Part 2: Short Answers & Calculations

4. Given rate = k[A]. A measured rate is 0.20 mol L^-1 s^-1 when [A] = 0.10 mol L^-1. Calculate k (include units).

5. For rate = k[A]^2, calculate the rate when k = 0.5 L mol^-1 s^-1 and [A] = 0.20 mol L^-1. Show working.

6. The concentration of A falls from 0.80 mol L^-1 to 0.60 mol L^-1 in 40 s. Calculate the average rate of reaction (use Δ[A]/Δt). Include units.

7. Rearrange rate = Δ[A]/Δt to find Δ[A]. If the average rate is 0.005 mol L^-1 s^-1 and the time is 120 s, what is Δ[A]? State whether concentration decreased or increased.

8. Explain in one or two sentences: If doubling [A] increases the rate by a factor of four, what is the reaction order with respect to A and why? _________