Questions
41
Which of the following statements about the catalyst is true?
Answer: A catalyst accelerates the rate of reaction by bringing down the activation energy.
42
Which among the following is a false statement?
Answer: Molecularity of a reaction may be zero or fraction.
43
What will be the fraction of molecules having energy equal to or greater than activation energy, Ea?
Answer: e-Ea/Rt
44
The half life of the first order reaction having rate constant K = 1.7 x 10-5s-1 is
Answer: 11.3 h
45
For a chemical reaction A→B, it is found that the rate of reaction doubles when the concentration of A is increased four times. The order of reaction is
Answer: Half
46
Activation energy of a chemical reaction can be determined by __________ .
Answer: determining the rate constants at two temperatures.
47
A first order reaction is 50% completed in 1.26 × 1014 s. How much time would it take for 100% completion?
Answer: infinite
48
If cone, of reactant ‘A’ is increased 10 times and rate of reaction becomes 100 times. What is order with respect to ‘A’?
Answer: 1
49
If the initial concentration of reactant is doubled, t1/2 is also doubled, the order of reaction is
Answer: zero
50
The rate of first order reaction is 0.04 mol L-1 s-1 at 10 sec. and 0.03 mol L-1 at 2C seconds after initiation of the reaction. t1/2 of reaction is
Answer: 24.1 s
51
A first order reaction has specific reaction rate 10-2s-1. How much time it will take for 20g of reactant to reduce to 5g?
Answer: 138.6 s
53
The half life period of first order reaction is 1386 seconds. The specific rate constant of the reaction is
Answer: 0.5 × 10-3 s-1
54
The rate constant of a reaction A → B is 0.6 × 103 mole per second. If the concentration of [A] is 5 M, then what will be concentration of [B] after 20 months?
Answer: 0.72 M
55
The rate of first order reaction is 0.04 mol L-1 s-1 at 10 sec. and 0.03 mol L-1 at 2C seconds after initiation of the reaction. t1/2 of reaction is
Answer: 24.1 s
56
Which of the following statements about the catalyst is true?
Answer: A catalyst accelerates the rate of reaction by bringing down the activation energy.
59
Colloidion is 4% solution of which one of the following in alcohol-ether mixture.
Answer: Nitrocellulose
60
The protective power of lyophilic colloidal sol is expressed in terms of
Answer: gold number
