At 518° C , the rate of decomposition of sample of gaseous acetaldehyde, initially at a pressure of 363 Torr, was 1. 00 Torr s-1 when 5 % had reacted and 0.5 Torr s-1 when 33 % had reacted. The order of the reaction is -

Question

At 518° C , the rate of decomposition of sample of gaseous acetaldehyde, initially at a pressure of 363 Torr, was 1. 00 Torr s-1 when 5 % had reacted and 0.5 Torr s-1 when 33 % had reacted. The order of the reaction is - (A) 2 (B) 3 (C) 1 (D) 0

Tardigrade Admin · Accepted Answer

Assume the order of reaction with respect to acetaldehyde is

x

.

Condition-1 :

Rate

= k [C H_{3} C H O]^{x}

1 = k [363 \times 0.95]^{x}

1 = k [344.85]^{x} ... (i)

Condition-2 :

0.5 = k [363 \times 0.67]^{x}

0.5 = k [243.21]^{x} ... (ii)

Divide equation (i) by (ii),

\frac{1}{0.5} = (\frac{344.85}{243.21})^{x}

\Rightarrow 2 = (1.414)^{x}

\Rightarrow x = 2

Q. At 518∘C , the rate of decomposition of sample of gaseous acetaldehyde, initially at a pressure of 363 Torr, was 1.00 Torr s−1 when 5% had reacted and 0.5 Torr s−1 when 33% had reacted. The order of the reaction is -

2

3

1

0

Assume the order of reaction with respect to acetaldehyde is x. Condition-1 : Rate =k[CH3​CHO]x 1=k[363×0.95]x 1=k[344.85]x...(i) Condition-2 : 0.5=k[363×0.67]x 0.5=k[243.21]x...(ii) Divide equation (i) by (ii), 0.51​=(243.21344.85​)x ⇒2=(1.414)x ⇒x=2

Q. At $51 8^{\circ} C$ , the rate of decomposition of sample of gaseous acetaldehyde, initially at a pressure of $363$ Torr, was $1.00$ Torr $s^{- 1}$ when $5%$ had reacted and $0.5$ Torr $s^{- 1}$ when $33%$ had reacted. The order of the reaction is -