NCERT Class 12 Chemistry Gk Questions & Answers
11 Which one of the following characteristics of the transistion metals is associated with higher catalytic activity?
Answer: Variable oxidation states
12 Which of the following are d-block elements but not regarded as transistion elements?
Answer: Zn, Cd, Hg
15 Helium is preferred to be used in balloons instead of hydrogen because it is
17 Which of the following is incorrect for KMnO4 to be used as an oxidising agent?
Answer: The number of electrons involved in oxidation of KMnO4 in acidic medium is 3.
19 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
20 Which of the following statements about the catalyst is true?
Answer: A catalyst accelerates the rate of reaction by bringing down the activation energy.