We’re being asked to calculate the rate for the formation of Cu(s).

Recall that the **average rate of a reaction** is given by:

$\overline{){\mathbf{Rate}}{\mathbf{=}}\frac{\mathbf{\u2206}\left[A\right]}{\mathbf{\u2206}\mathbf{time}}}$

where:**Δ[A]** = change in concentration of reactants or products (in mol/L or M) **Δtime** = change in time.

What is the rate for the formation of Cu(s) in the reaction Cu^{2+}(aq) + H_{2}(g) ⇌ Cu(s) + 2 H^{+}(aq) if Δ[H^{+}] / Δt = 1.2 x 10 ^{-3 }?

1. 6 x 10^{-4}

2. 2.4 x 10^{-3}

3. 1.2 x 10^{-3}

4. 3 x 10^{-4}

5. 2 x 10^{-4}