pH value of which one of the following is not equal to one?

• 0.1 M HNO₃

• 0.05 M H₂SO₄

• 0.1 M CH₃COOH

• 50 cm³ of 0.4 M HCl + 50 cm³of 0.2 M NaOH

Which one of these is not true for benzene?

• It forms only one type of monosubstituted product

• There are three carbon-carbon single bonds and three carbon-carbon double bonds

• The heat of hydrogenation of benzene is less than the theoretical value

• The bond angle between the carbon-carbon bonds is 120°

Generally, the first ionization energy increases along a period. But there are some exceptions. One which is not an exception is

• N and O

• Na and Mg

• Mg and Al

• Be and B

Which one of the following conformations of cyclohexane is the least stable?

• Half-chair

• Boat

• Twisted-boat

• Chair

Which one of the following is a molecular crystal?

• Rock salt

• Quartz

• Dry ice

• Diamond

26.

Chloroacetic acid is a stronger acid than acetic acid. This can be explained using

• -M effect

• - I effect

• +M effect

• +I effect

For alkali metals, which one of the following trends is incorrect?

• Hydration energy : Li > Na > K > Rb

• Ionization energy : Li > Na > K > Rb

• Density : Li < Na < K < Rb

• Atomic size : Li < Na < K < Rb

A dibromo derivative of an alkane reacts with sodium metal to form an alicyclic hydrocarbon. The derivative is

• 1, 1-dibromopropane

• 2, 2-dibromobutane

• 1, 2-dibromoethane

• 1, 4-dibromobutane

In the electrolytic refining of zinc

• graphite is at the anode

• the impure metal is at the cathode

• the metal ion get reduced at the anode

• acidified zinc sulphate is the electrolyte

In chromite ore, the oxidation number of iron, and chromium are respectively

• +3,+2

• +3,+6

• +2,+6

• +2,+3