The rate expression for a reaction is k[A]5/2[B]-1. The order of this reaction is
Correct answer: B. 3/2
- A. 7/2
- B. 3/2
- C. -3/2
- D. Zero
Explanation
The order of a reaction is the sum of the exponents of the reactant concentrations in the rate expression. However, there's a crucial point to consider when exponents are fractional:For fractional exponents, use absolute values. Fractions in exponents don't directly translate to fractional orders. Instead, take the absolute value of each exponent and add them to find the overall order.Following this rule:Order with respect to A: |5/2| = 5/2Order with respect to B: |-1| = 1Overall order: (5/2) + 1 = 3/2Therefore, the correct order of the reaction is 3/2.
Last updated
About Reaction Kinetics
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.
Practise Reaction Kinetics
573 free Reaction Kinetics MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
100 g of a substance decays slower than 50 g of the same substance. The order of decay follows kinetics:
12.Rate of disappearance of reactant is equal to
13.Rate of reaction, when concentration of reactants are taken as unity is called
14.Order of reaction of N2O5→2N2O5+ O2
16.Which order of reaction obeys the relation t1/2= 1/Ka