For a chemical reaction:
A + B → Products
| Experiment | \(\frac{[A]}{mol L^{-1}}\) | \(\frac{[B]}{mol L^{-1}}\) | \(\frac{\text{Initial rate}}{mol L^{-1} s^{-1}}\) |
| 1. | 0.1 | 0.1 | 2.0 x 10-3 |
| 2. | 0.2 | 0.2 | 4.0 x 10-3 |
| 3. | 0.1 | 0.2 | 2.0x 10-3 |
What is the overall order of chemical reaction?
Answer & explanation
Correct answer: option 2
A + B → Products
Rate of reaction = k [A]x [B]y
2.0 x 10-3 = k [0.1]x [0.1]y .....(i)
4.0 x 10-3 = k [0.2]x [0.2]y ......(ii)
2.0 x 10-3 = k [0.1]x [0.2]y ......(iii)
Divide (iii) By (i), we get
\(\frac{2.0 × 10^{-3}}{2.0 × 10^{-3}}\) = \(\frac{k[0.1]^x[0.2]^y}{k[0.1]^x[0.1]^y}\)
1 = 2y
20 = 2y
y = 1
Divide (ii) by (iii), we get
\(\frac{4.0 × 10^{-3}}{2.0 × 10^{-3}}\) = \(\frac{k[0.2]^x[0.2]^y}{k[0.1]^x[0.2]^y}\)
2 = 2x
21 = 2x
x = 1
Overall order = x + y = 1 + 0 = 1