NCERT Class 12 Chemistry General Awareness Questions with Answers
61 Which of the following statements about the catalyst is true?
Answer: A catalyst accelerates the rate of reaction by bringing down the activation energy.
62 Which among the following is a false statement?
Answer: Molecularity of a reaction may be zero or fraction.
63 A solution containing 10 g per dm3 of urea (molar mass 60 g mol-1) is isotonic with 5% solution of non-volatile solute, MB of solute is
Answer: 300 g mol-1
65 Which of the following reactions is an example of auto reduction?
Answer: Cu20 + 1/2 Cu2S → 3Cu + 1/2 SO2
66 The electrolytic reduction technique is used in the extraction of
Answer: Highly electropostive elements.
67 If molality of dilute solution is doubled, the value of molal depression constant (Kf) will be
Answer: unchanged
68 Which one of the following metals is required as cofactor by all enzymes utilizing ATP in phosphate transfer?
Answer: Mg
69 An unripe mango placed in a concentrated salt solution to prepare pickle, shrivels because _________ .
Answer: it loses water due to reverse osmosis.
70 What will be the fraction of molecules having energy equal to or greater than activation energy, Ea?
Answer: e-Ea/Rt