Decomposition of A is a first order reaction at T (K ) and is given by A (g ) ⟶B (g )+C (g ). In a closed 1 L vessel, 1 bar A (g ) is allowed to decompose at T (K ). After 100 minutes, the total pres…

Question

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

Accepted Answer

Correct answer: A. (a) For the reaction A (g ) B (g )+C (g ), initially pressure of A is 1 bar. Initially: total pressure =1 bar. After 100 min : total pressure =1.5 bar. Using initial and final pressures, if x bar of A decomposes, then A becomes (1-x ) ,B=x ,C=x. Total pressure =1-x+x+x=1+x=1.5, so x=0.5 bar. For a first-order reaction: k= 2.303t log ⁡ [A ]_0 [A ]. Using pressures instead: k= 2.303100 log ⁡ 10.5 = 2.303100 log2= 2.303 0.3100= 0.691100 =6.91 10^-3 min^-1 ≈6.9 10^-3 min^-1

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

Solution

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