(a) For the reaction $2\text{N}_2\text{O}_{5(g)} \rightarrow 4\text{NO}_{2(g)} + \text{O}_{2(g)}$ at $318\text{ K}$ calculate the rate of reaction if rate of disappearance of $\text{N}_2\text{O}_{5(g)}$ is $1.4 \times 10^{-3}\text{ m s}^{-1}$. (b) For a first order reaction derive the relationship $t_{99%} = 2t_{90%}$

Year	Paper Code	Set	Position
CBSE 2023	Series Other	Set 1	Question 26
CBSE 2023	Series Other	Set 1	Question 29
CBSE 2023	Series Other	Set 1	Question 30

• Step 1: Stating the fundamental formula / law statement (+1 Mark)
• Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
• Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)