Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Chemical Kinetics and Nuclear Chemistry question

2003 · Shift 0 · Q42
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Chemistry
  4. /Chemical Kinetics and Nuclear Chemistry
  5. /2003 · Shift 0 · Q42

Chemical Kinetics and Nuclear Chemistry question

2003 · Shift 0 · Q42

JEE MainChemistryChemical Kinetics and Nuclear ChemistryMCQ+4 / −1
For the reaction system: 2NONONO(g) + O2O_2O2​(g) →\to→ 2NO2NO_2NO2​(g) volume is suddenly reduce to half its value by increasing the pressure on it. If the reaction is of first order with respect to O2O_2O2​ and second order with respect to NONONO, the rate of reaction will
  1. A
    diminish to one-eighth of its initial value
  2. B
    increase to eight times of its initial value
  3. C
    increase to four times of its initial value
  4. D
    diminish to one-fourth of its initial value
View written solutionFree

Correct answer: B

  1. Write the rate law

For the reaction 2NO(g)+O2(g)→2NO2(g)2NO(g) + O_2(g) \to 2NO_2(g)2NO(g)+O2​(g)→2NO2​(g)

given that it is:

  • second order with respect to NONONO
  • first order with respect to O2O_2O2​

the rate law is r=k[NO]2[O2]r = k[NO]^2[O_2]r=k[NO]2[O2​]

  1. Effect of reducing volume to half

If the volume is suddenly reduced to half, the concentrations of all gases become double, because [concentration]∝1V[\text{concentration}] \propto \frac{1}{V}[concentration]∝V1​

So, [NO]′=2[NO][NO]' = 2[NO][NO]′=2[NO] [O2]′=2[O2][O_2]' = 2[O_2][O2​]′=2[O2​]

  1. Calculate the new rate

Substitute into the rate law: r′=k([NO]′)2([O2]′)r' = k([NO]')^2([O_2]')r′=k([NO]′)2([O2​]′) r′=k(2[NO])2(2[O2])r' = k(2[NO])^2(2[O_2])r′=k(2[NO])2(2[O2​])

Now simplify: r′=k⋅4[NO]2⋅2[O2]r' = k \cdot 4[NO]^2 \cdot 2[O_2]r′=k⋅4[NO]2⋅2[O2​] r′=8k[NO]2[O2]r' = 8k[NO]^2[O_2]r′=8k[NO]2[O2​]

But r=k[NO]2[O2]r = k[NO]^2[O_2]r=k[NO]2[O2​]

Hence, r′=8rr' = 8rr′=8r

  1. Conclusion

The rate becomes eight times the initial value.

Therefore, the correct option is: B\boxed{\text{B}}B​

PreviousNext

More from Chemical Kinetics and Nuclear Chemistry

  • Units of rate constant of first and zero order reactions in terms of molarity M unit are respectively2002 · MCQ
  • For the reaction A + 2B → C, rate is given by R = [A] [B]2 then the order of the reaction is2002 · MCQ
  • The differential rate law for the reaction H2​ + I2​ → 2HI is2002 · MCQ
  • If half-life of a substance is 5 yrs, then the total amount of substance left after 15 years, when initial amount is 64 grams is2002 · MCQ
  • β - particle is emitted in radioactivity by2002 · MCQ
  • The integrated rate equation is Rt = log C0 - log Ct . The straight line graph is obtained by plotting2002 · MCQ
  • For the reaction A → products. The concentration of A at 10 minutes is ​×10−3 mol L−1(nearest integer). The reaction was started with 2.5 mol L−1 of A . Includes diagram2025 · Numerical
  • Reactant A converts to product D through the given mechanism (with the net evolution of heat): A → B slow; ΔH = +ve B → C fast; ΔH = -ve C → D fast; ΔH = -ve Which of the following represents the above reaction mechanism?2025 · MCQ