CBSE
Multiple Choice QuestionsFor the reaction A(g)B( g)+ C(g), the rate constant is given as (Pi is initial pressure and Pt is pressure at time t)
The activation energy for most of the reactions is approximately 50 kJ mol-1 .The value of temperature coefficient for such reactions is :
> 2
> 3
< 1
> 4
Which one of the following options is not correct for the decomposition reaction of NH3 ?
2NH3 (g) N2 (g) + 3H2 (g)
Rate of reaction = rate constant
Further increase in pressure will change the rate of reaction
Rate of decomposition of NH3 will remain constant until NH3 disappears completely
Rate of reaction depends on concentration of NH3
75% of a zero order reaction complete in 4 h 87.5% of the same reaction completes in
6h
12h
8h
2h
For the reaction , aA + bB cC , if -3 = -3 = +1.5 then a , b , c respectively are :
1 , 3 , 2
1 , 2 , 3
3 , 2 , 1
3 , 1 , 2
The role of a catalyst is to change :
enthalpy of reaction
equilibrium constant
activation energy of reaction
Gibbs energy of reaction
For reaction aA xP, when [A] = 2.2 mM, the rate was found to be 2.4 mM s-1. On reducing concentration of A to half, the rate changes to 0.6 mM s-1.The order of reaction with respect to A is
1.5
2.0
2.5
3.0
If the rate of reaction , A B doubles on increasing the concentration of A by 4 times , the order of the reaction is :
2
1
0.5
4
For a first order reaction at 27°C , the ratio of time required for 75% completion to 25% completion of reaction is :
log
log
The plot of a concentration of the reactant versus time for a reaction is a straight line with a negative slope. The reaction follows a
first order rate equation
zero order rate equation
second order reaction
third order rate equation
