JEE Main · 2022 · 24 Jun 2022 · Shift 1 · Chemical Kinetics

WhatsApp Email

The rate constants for decomposition of acetaldehyde have been measured over the temperature range 700-1000 K. The data has been analysed by plotting ln k vs 10³/T graph. The value of activation energy for the reaction is ______ kJ mol⁻¹. (Nearest integer) (Given: R = 8.31 J K⁻¹ mol⁻¹)

Answer: 154

Solution

The Arrhenius equation in logarithmic form is: ln k = ln A - Ea/(RT). When plotted as ln k vs 10³/T, the slope = -Ea/(R × 10³). From the graph, slope = -18.5. Therefore: -Ea/(8.31 × 10³) = -18.5. Ea = 18.5 × 8.31 × 10³ = 153735 J/mol = 153.7 kJ/mol ≈ 154 kJ/mol.

JEE Main · 2022 · 24 Jun 2022 · Shift 1 · Integer answer

Practise more: all JEE Main PYQs on Chemical Kinetics →

More JEE Main questions on Chemical Kinetics

Pre-exponential factors of two different reactions of same order are identical. Let activation energy of first reaction exceeds the activation energy of second reaction by $20 kJ mol^{- 1}$ . If $k_{1}$ and $k_{2}$ are the rate constants of fir …
JEE Main 2026View solution →
A → products (First order reaction).

Three sets of experiment were performed for a reaction under similar experimental conditions.
Run $1 \Rightarrow 100 mL$ of 10 M solution of reactant A
Run $2 \Rightarrow 200 mL$ of 10 M solution of reactant A
Run …
JEE Main 2026View solution →
The temperature at which the rate constants of the given below two gaseous reactions become equal is
____ K. (Nearest integer).
$X ⟶ Y k_{1} = 1 0^{6} e^{\frac{- 30000}{T}}$ …
JEE Main 2026View solution →
Decomposition of A is a first order reaction at $T (K)$ and is given by $A (g) \to B (g) + C (g)$ . In a closed 1 L vessel, 1 bar $A (g)$ is allowed to decompose at $T (K)$ . …
JEE Main 2026View solution →
Correct statements regarding Arrhenius equation among the following are :
(A) Factor $e^{- Ea / RT}$ corresponds to fraction of molecules having kinetic energy less than Ea.
(B) At a given temperature, lower the Ea, faster is the reaction.
(C) Increase in tempe …
JEE Main 2026View solution →
Consider $A k_{1} B$ and $C k_{2} D$ are two reactions. If the rate constant $(k_{1})$ of the $A \to B$ reaction can be expressed by the following equation …
JEE Main 2026View solution →