For a first-order reaction A Products, the rate of reaction at [A] = 0.2 M is 1.0 x 10-2 mol litre-1 min-1. The half-life period for the reaction will be:
1. | 832 sec | 2. | 440 sec |
3. | 416 sec | 4. | 14 sec |
The rate of a chemical reaction doubles for every 10°C rise of temperature. If the temperature is raised by 50°C, the rate of the reaction increases by about :
1. 10 times
2. 24 times
3. 32 times
4. 64 times
Consider the reaction:
Cl2(aq) + H2S(aq) → S(s) +2H+(aq) +2Cl-(aq)
The rate equation for this reaction is rate = k[Cl2][H2S] Which of these mechanisms is/are consistent with this rate equation?
A. Cl2 + H2S → H+ + Cl- +Cl+ + HS- (slow)
cl+ + HS- → H+ +Cl- + S (fast)
B. H2S H+ + HS- (fast equilibrium)
Cl2 + HS- → 2Cl- + H+ + S (slow)
1. A only
2. B only
3. Both A and B
4. Neither A nor B
A graph plotted between log (t) 50% vs. log (a) concentration is a straight line. What conclusion can you draw from the given graph?
1. n=1, t1/2 = 1/K.a
2. n=2, t1/2 = 1/a
3. n=1, t1/2 = 0.693/K
4. None of the above
In acidic medium the rate of reaction between BrO3- and Br- ions is given by the expression
It means:
1. | The rate constant of the overall reaction is 4 sec-1. |
2. | The rate of reaction is independent of the concentration of the acid. |
3. | The change in pH of the solution will not affect the rate. |
4. | Doubling the concentration of H+ ions will increase the rate of reaction by 4 times. |
If concentration of reactants is increased by 'X', the rate constant K becomes:
1. eK/X
2. K/X
3. K
4. X/K
The rate constant of a first-order reaction is\(4 \times 10^{-3} \mathrm{sec}^{-1}.\) At a reactant concentration of \(0.02~\mathrm{M},\) the rate of reaction would be:
1. | \(8 \times 10^{-5} \mathrm{M} ~\mathrm{sec}^{-1} \) | 2. | \(4 \times 10^{-3} \mathrm{M} ~\mathrm{sec}^{-1} \) |
3. | \(2 \times 10^{-1} \mathrm{M}~ \mathrm{sec}^{-1} \) | 4. | \(4 \times 10^{-1} \mathrm{M}~ \mathrm{sec}^{-1}\) |
For the reaction , at the point of intersection of two curves show, the [B] is can be given by:
1.
2.
3.
4.
The following mechanism has been proposed for the reaction of NO with Br2 to form NOBr:
NO(g) + Br2(g) NOBr2(g)
NOBr2(g) + NO(g) 2NOBr(g)
If the second step is the rate determining step, the order of the reaction with respect to NO(g) will be:
1. 1
2. 0
3. 3
4. 2
In a first order reaction, the concentration of the reactant is decreased from 1.0 M to 0.25M in 20 minute. The rate constant of the reaction would be:
1. 10min-1
2. 6.931 min-1
3. 0.6931 min-1
4. 0.06931 min-1