Chemistry Top MCQs – 4

The following are the half lives of four active isotopes. Which one of the following is the most dangerous to handle?
(A) 3 billion years
(B) 100 years
(C) 0.01 minute
(D) 13 days
Answer: Option C

The high reactivity of fluorine is due to
(A) Its high electro negativity
(B) Small size of fluorine atom
(C) Availability of d-orbitals
(D) Strong F – F bond
Answer: Option A

The metal does not give H2 on treatment with dilute HCL is
(A) Zn
(B) Fe
(C) Ag
(D) Ca
Answer: Option C

The maximum number of isomers for an alkene with molecular formula C4H8 is
(A) 5
(B) 4
(C) 2
(D) 3
Answer: Option B

The human body is made up of several chemical elements; the element present in the highest proportion (65%) in the body is
(A) Carbon
(B) Hydrogen
(C) Oxygen
(D) Nitrogen
Answer: Option C

The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in
(A) 1.8 gram of H2O
(B) 12 moles of KMnO4
(C) 0.6 N H2SO4
(D) 4.6 gram of C2H5OH
Answer: Option B

The formula C6H5-CO-CH3 represents
(A) Acetone
(B) Acetic acid
(C) Acetophenone
(D) Phenyl acetate
Answer: Option C

The names of the scientists, Newlands, Mendeleev, and Meyer are associated with the development of
(A) Atomic structure
(B) Metallurgy
(C) Periodic table of contents
(D) Discovery of elements
Answer: Option C

The metal that is used as a catalyst in the hydrogenation of oils is
(A) Ni
(B) Pb
(C) Cu
(D) Pt
Answer: Option A

The number of moles of solute present in 1 kg of a solvent is called its
(A) Molality
(B) Molarity
(C) Normality
(D) Formality
Answer: Option A

Nowadays many novel chemicals are being synthesized termed as xenobiotics. The unique feature of these is what they are I. Biodegradable
II. Non-biodegradable
III. Pose on environmental threat
IV. They are environment friendly
(A) I, III
(B) II, III
(C) I, III, IV
(D) II, III, IV
Answer: Option B