What will be order of reaction if doubling the concentration of reactant increases the rate by a factor of 4 and tripling the concentration of reactant increases the rate by a factor of 9.
Correct answer: C. 2
- A. 1
- B. 3
- C. 2
- D. 0
Explanation
If the concentration is doubled then the ratio is= 2 Rate quadruples when concentration doubles, so the ratio of rate = 4 Order of reaction = n Ratio of concentrationn = ratio of rate ; 2n = 4 ==> 22 = 4 ∴ n = 2. {Cross check with the 2nd condition} If the concentration is tripled then the ratio is= 3 Rate increases 9 times when concentration triples, so the ratio of rate = 9 Order of reaction = n Ratio of concentrationn = ratio of rate; 3n = 9 ==> 32 = 9 ∴ n = 2.
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Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.
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