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Chemistry · 2024 · 2 marks
CBSE 2024 · Region 3 · Set 1 · Q18
(a) In a reaction, if the concentration of reactant ' X ' is tripled, the rate of reaction becomes twenty-seven times. What is the order of the…
(a)
In a reaction, if the concentration of reactant ' X ' is tripled, the rate of reaction becomes twenty-seven times. What is the order of the reaction?
(b)
State a condition under which a bimolecular reaction is kinetically a first-order reaction. Give an example of such a reaction.
Marking-scheme solution
(a)
Rate \(\displaystyle =\mathrm{k}[\mathrm{X}]^{\mathrm{p}}\)
\[\begin{aligned}
27 \text { Rate } & =\mathrm{k}[3 \mathrm{X}]^{\mathrm{p}} \\
& \therefore 27=3^{\mathrm{p}}
\end{aligned}
\]
\(\displaystyle (3)^{3}=3^{\mathrm{p}}\)
\(\displaystyle \mathrm{p}=3 \quad\) Third order
/ Third order
(b)
When one of the reactants is in excess.
Example : Hydrolysis of ester / sucrose
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