11th class (FSc) chemistry Unit 11 MCQs
21. A substance which retards the rate of reaction is called:
a. Oxidant
b. Inhibitor
c. Auto-Catalyst
d. Activator
22. Sugar solution hydrolyses to glucose and fructose in the presence of enzyme:
a. Zymase
b. Urease
c. Invertase
d. None of these
23. Glucose is converted into ethanol by the enyme:
a. Zymase
b. Invertase
c. Sucrase
d. Urease
24. The Enzyme used for hydrolysis of urea is:
a. Lipase
b. Invertase
c. Zymase
d. Urease
25. In a zero order reaction. the rate is independent of:
a. Concentration of products
b. Temperature of reaction
c. Concentration of reaction
d. None of these
26. If the rate equation of a reaction 2A → B products is: Rate = K[A]2 [B] and A is present in large excess, then order of reaction is:
a. 3
b. 1
c. 2
d. None of these
27. The rate of reaction:
a. Remains the same as the reaction proceeds
b. Increase as the reaction proceeds
c. May decrease or increase as the reaction proceeds
d. Decreased as the reaction proceeds
28. with increase of 10oC temperature the rate of reaction doubles. this is due to:
a. Increase in activation energy of reactions
b. Decrease in the activation energy of reaction
c. Increase in the number of effective collision
d. Decrease in the number of collision between molecules
29. The unit of rate constant is the same as that rate of reaction is:
a. Zero order reaction
b. First order reaction
c. Third order reaction
d. Second order reaction
30. According to collision theory of bimolecular reaction sin gas phase, the minimum amount of energy required for an effective collision is known as:
a. Has no effect on the reaction
b. Heat of reaction
c. Energy of activation
d. Rate of reaction
31. In some reactions, a product formed acts as a catalyst. Thephenomenon is called:
a. Heterogeneous catalysis
b. Negative catalysis
c. Autocatalysis
d. Activation of catalyst
32. The reaction rate in forward reaction decreases with the passage of time:
a. The order of reaction changes
b. Concentration of reactions decrease
c. Temperature of the system changes
d. Concentration of product decrease
33. In zero order reaction the rate is indepentent of:
a. Temperature of the reaction
b. Concentration of the product
c. Surface area of the product
d. Concentration of the ractant
34. If the reactant or product of a chemical reaction can absorb ultraviolet or infrared radiation, then the rate of a chemical reaction can best be measured by which one of the following method?
a. Graphical method
b. Chemical method
c. Differental method
d. Spectrometry
35. For the reaction 2NO+02=2NO2, the rate equation for the forward reaction is:
a. Rate=K [NO2]2
b. Rate=K [NO] [O2]
c. Rate=K [NO2]
d. Rate=K[NO]-2 [O2]
36. The half-life of N2OS at 0oC is minutes. How long will it take for sample of N2OS to decay to 25% of its original conentration?
a. 72 minutes
b. 24 minutes
c. 48 minutes
d. 120 minutes
37. When the change in concentration is 6 x 104 mol dm3 and time for that change is 10 seconds. the role of reaction:
a. 6 x 102mol dm-3 sec-1
b. 6 x 103mol dm–1 sec1
c. 6 x 10-3mol dm-3 sec1
d. 6 x 104mol dm-3
38. 2A + B → product . if the reaction B is in excess, the order of reaction with respect to A in given rate law rate =k[A]2[B]
a. Pseudo 1st order reaction
b. 2nd order reaction
c. 3rd order reaction
d. 1st order reaction
39. The rate constant K is 0.693 min-1 The half-life for the 1st order reaction will be:
a. 0.693 min
b. 1 min
c. 4 min
d. 2 min
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