For the thermal decomposition of reaction $\ce{AB(g)}$, the following is constructed. The half life of the reaction is 'x' min. $x =$ \_\_\_\_ min. (Nearest integer)

JEE Main · 2026 · 23 Jan 2026 · Shift 1 · Chemical Kinetics

For the thermal decomposition of reaction

AB (g)

, the following is constructed.

The half life of the reaction is 'x' min.

x =

____ min. (Nearest integer)

Answer: 10

The plot of

[AB]

against time is a straight line with negative slope, the signature of a zero-order reaction,

[AB] = [AB]_{0} - k t

. From the graph the concentration falls from

0.60 M

t = 0

0.55 M

t = 100 s

, so

k = \frac{0.60 - 0.55}{100} = 5 \times 1 0^{- 4} M s^{- 1}

. For a zero-order reaction the half-life is

t_{1/2} = \frac{[ AB ] _{0}}{2 k} = \frac{0.60}{2 \times 5 \times 1 0 ^{- 4}} = 600 s

, which is 10 min.

JEE Main · 2026 · 23 Jan 2026 · Shift 1 · Integer answer