PYQ Vault
EbooksTutor

First-order gas decomposition followed by total pressure

This type of question, asked 6 times: 13 Apr 2023, 1 Feb 2024, 9 Apr 2024, 23 Jan 2025, 7 Apr 2025, 21 Jan 2026 S2. All 6 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    13 Apr 2023

    147
    A(g)→2 B( g)+C(g)A(g) \rightarrow 2\text{ }B(\text{ }g) + C(g) is a first order reaction. The initial pressure of the system was found to be 800 mmHg800\text{ }mmHg which increased to 1600 mmHg1600\text{ }mmHg after 10 min⁡10\text{ }\min. The total pressure of the system after 30 min⁡30\text{ }\min will be ___mmHg\_\_\_ mmHg. (Nearest integer)

  2. Question 2

    1 Feb 2024

    142
    The following data were obtained during the first order thermal decomposition of a gas AA at constant volume:
    A(g)→2 B( g)+C(g)A(g) \rightarrow 2\text{ }B(\text{ }g) + C(g)
    S. No.Time/sTotal pressure/atm
    100.1
    21150.28
    The rate constant of the reaction is ______ ×10−2 s−1\times10^{- 2}{\text{ }s}^{- 1} (nearest integer)

  3. Question 3

    9 Apr 2024

    145
    Consider the following first order gas phase reaction at constant temperature
    A(g)→2 B( g)+C(g)A(g) \rightarrow 2\text{ }B(\text{ }g) + C(g)
    If the total pressure of the gases is found to be 200 torr after 23sec23sec. and 300 torr upon the complete decomposition of A after a very long time, then the rate constant of the given reaction is ____ ×10−2 s−1\times10^{- 2}{\text{ }s}^{- 1} (nearest integer) [Given: log⁡102=0.301\log_{10}2 = 0.301 ]

  4. Question 4

    23 Jan 2025

    49
    For the thermal decomposition of N2O5( g)N_{2}O_{5}(\text{ }g) at constant volume, the following table can be formed, for the reaction mentioned below :
    2 N2O5( g)→2 N2O4( g)+O2( g)2{\text{ }N}_{2}O_{5}(\text{ }g) \rightarrow 2{\text{ }N}_{2}O_{4}(\text{ }g) +O_{2}(\text{ }g)
    S. No.Time/sTotal pressure/atm
    100.6
    2100xx
    x=x = ____\_\_\_\_ ×10−3 atm\times10^{- 3}\text{ }atm [nearest integer] Given : Rate constant for the reaction is 4.606×10−2 s−14.606 \times10^{- 2}{\text{ }s}^{- 1}.

  5. Question 5

    7 Apr 2025

    28
    Reaction A(g)→2 B( g)+C(g)A(g) \rightarrow 2\text{ }B(\text{ }g) + C(g) is a first order reaction. It was started with pure A
    t/minPressure of system at time t/mm Hg
    10160
    ∞\infty
    		240
    Which of the following option is incorrect ?

    Tap an option to check your answer.

  6. Question 6

    21 Jan 2026 S2

    33
    Decomposition of A is a first order reaction at T(K)T(K) and is given by A(g)→B(g)+C(g)A(g) \rightarrow B(g) + C(g). In a closed 1 L vessel, 1 bar A(g)A(g) is allowed to decompose at T(K)T(K). After 100 minutes, the total pressure was 1.5 bar. What is the rate constant (in min⁡−1\min^{- 1}) of the reaction ? (log⁡2=0.3\log2 = 0.3)

    Tap an option to check your answer.