The reaction A → B follows first order kinetics. The time taken for 0.8 mole of A to produce 0.6 mole of B is 1 hour. The time taken for conversion of 0.9 mole of A to produce 0.675 mole of B is :
1 hour
0.5 hour
0.25 hour
2 hour
If the rate of the reaction is equal to the rate constant, the order of the reaction is -
0
1
2
3
The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation,k = A.e–E*/RT. Activation energy (E*) of the reaction can be calculated by plotting :
k vs T
k vs 1log T
log k vs 1T
log k vs 1logT
The radioisotope, tritium (H13) has a half-life of 12.3 years. If the initial amount of tritium is 32 mg, how many milligrams of its would remain after 49.2 years :
1 mg
2 mg
4 mg
8 mg
The decomposition of NH3 on platinum surface is a zero order reaction. The rates of production of N2 and H2 if k = 2.5 × 10–4 mol–1 L s–1 will be respectively -
2.5 x 10-4 mol L-1 s-1 and 5.5 x 10-4 mol L-1 s-1
2.5 x 10-4 mol L-1 s-1 and 7.5 x 10-4 mol L-1 s-1
1.5 x 10-4 mol L-1 s-1 and 4.5 x 10-4 mol L-1 s-1
0.5 x 10-4 mol L-1 s-1 and 3.5 x 10-4 mol L-1 s-1
The rate equation of a reaction is expressed as, Rate=K (PCH3OCH3)32
(Unit of rate = bar min-1)
The units of the rate constant will be:
1. bar1/2 min 2. bar2 min-1 3. bar-1 min-2 4. bar-1/2min-1
The factor(s) that affect the rate of a chemical reaction is/are -
Concentration/Pressure of reactants.
Temperature
Presence of a catalyst
All of the above
The correct statement about the rate constant of a reaction is-
Rate constant is nearly doubled with a rise in temperature by 10°
Rate constant becomes half with a rise in temperature by 10°
Rate constant remains unchanged with a rise in temperature by 10°
None of the above
The average rate of reaction between the time interval 30 to 60 seconds in the above-mentioned
pseudo 1st order reaction is-
1. 6.67 ×10-2 mol L-1 s-12. 2.67 × 10-4 mol L-1 s-1 3. 4.67 × 10-3 mol L-1 s-14. 4.27 × 103 mol L-1 s-1
A reaction is first order with respect to A and second-order with respect to B. The concentration of B is increased three times. The new rate of the reaction would :
Decrease 9 times.
Increase 9 times.
Increase 6 times.
Decrease 6 times.
In a reaction between A and B, the initial rate of reaction (r0) was measured for different initial concentrations of A and B as given below:
The order of the reaction with respect to A and B would be -
The order w.r.t A is 0.5 and w.r.t B is zero.
The order w.r.t A is 1 and w.r.t B is 0.5
The order w.r.t A is 2 and w.r.t B is 1
The order w.r.t A is 1.5 and w.r.t B is zero
For a reaction, 2A + B → C + D , following observations were recorded:
The rate law applicable for the above mentioned reaction would be -
Rate = k[A]2[B]3
Rate = k[A][B]2
Rate = k[A]2[B]
Rate = k[A][B]
Given the following observations:
The reaction between A and B is first-order with respect to A and zero-order with respect to B. The value of X and Y are, respectively :
X = 0.2 mol L-1; Y = 0.08 mol L-1min-1
X = 0.02 mol L-1; Y = 0.08 mol L-1min-1
X = 0.01 mol L-1; Y = 0.8 mol L-1min-1
X = 0.2 mol L-1; Y = 0.8 mol L-1min-1
The rate constant of a radioactive substance is 4 years-1. The value of half-life will be :
0.05 years
0.17 years
0.26 years-1
1.6 years
During a nuclear explosion, one of the products is 90Sr with a half-life of 28.1 years. If 1µg of 90Sr was absorbed in the bones of a newly born baby instead of calcium, the amount of 90Sr that will remain after 10 years in the now grown up child would be -
0.227 µg
0.781 µg
7.81 µg
2.27 µg
For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data was obtained:
The rate constant of the above reaction would be -
1.21 x 10-3 s-1
2.21 x 10-3 s-1
3.21 x 10-3 s-1
4.21 x 10-3 s-1
For the reaction 2A + B→A2B, rate = kAB2 with k = 2.0×10-6 mol-2L2s-1 and A=0.1 M; B=0.2 M. The initial rate of the reaction will be
0.04×10-9 mol L-1 s-1
8×10-8 mol-1L s-1
8×10-9 mol L-1 s-1
8×10-7 mol L-1 s-1
For a first-order reaction, the relationship between time required for 99% completion to the time required for the completion of 90% of the reaction would be
1. t99% = 3 t90%2. t99% = 2 t90%3. t99% = 4 t90%4. t90% = 2t99%
Given that Rate=kH2O2I-. The dimension of the rate constant in the given rate law is -
molL-1s-1
mol-1Ls-1
mol-1Ls-2
mol-2Ls-1
Consider the following rate expression.
Rate=kCH3CHO32
The order of reaction and dimension of the rate constant are, respectively-
32; k = mol-1Ls-1
3; k = mol-1Ls-1
32; k = mol12L-12s-1
32; k = mol-12L12s-1
If the concentration of the reactant is made twice, the new rate of reaction for the second order reaction would be-
2 times
4 times
3 times
No change in the rate of the reaction
A first-order reaction takes 40 min for 30% decomposition. Half life of the reaction is-
55.9 min
77.9 min
63.9 min
80.9 min
The rate constant for a first-order reaction is 60 s-1. The time required to reduce the initial concentration of the reactant to its 1/16 value is-
5.64×10-2 s
6.64×10-2 s
4.62×10-2 s
0.14×10-2 s
The time required for 10% completion of a first-order reaction at 298K is equal to that required for its 25% completion at 308K. The value of Ea is :
76.64 J mol-1
66.64 kJ mol-1
76.64 kJ mol-1
70.34 kJ mol-1
The average rate of reaction based on the above graph will be :
1.R2-R1t2-t12. - R2-R1t2-t13. R2t24. -R1-R2t2-t1
Consider the following graph.
The instantaneous rate of reaction at t= 600 sec will be :
1. - 4.75 ×10-4 mol L-1s-12. 5.75×10-5 mol L-1s-13. 6.75×10-6 mol L-1s-14. -6.75×10-6 mol L-1s-1
The slope for the given graph is-
1. k2.3032. -k2.3033. -2.303k4. 2.303k
Consider the following graph:
The nature of the reaction represented in the above-mentioned graph is :
Endothermic reaction
Exothermic reaction
Both endothermic and exothermic reactions are represented by the same graph.
The graph between lnK, and 1Tis given below:
The value of activation energy would be -
1. 207. 8 kJ/mol2. -207. 8 kJ/mol3. 210.8 kJ/mol4. -210.8 kJ/mol
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