If n = overall order of a chemical reaction. a = initial concentration of reactant. t = time required to complete a definite fraction of the reaction. Then pick out the correct relationship ?

A. Lessens its selectivity
B. May be useful for suppressing undesirable side reactions
C. Is added in small quantity during the catalyst manufacture itself
D. All A., B. and C.

A. More
B. Less
C. Same
D. Either A. or B., depends on order of reaction

A. Less than
B. Equal to
C. More than
D. Equal to or more than

A. Increase of temperature
B. Decrease of temperature
C. Increase in initial concentration of A
D. Decrease in initial concentration of A

A. The rate of disappearance of ‘Y’ is equal to the rate of appearance of ‘Z’
B. The rate of disappearance of ‘Y’ is equal to the rate of disappearance of ‘X’
C. Three times the rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’
D. The rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’

A. Are the same as those of the rate constant
B. Depend on the order of the reaction
C. Depend on temperature, pressure etc. of the reaction
D. Are cycles per unit time