True or False type question chemistry - Periodic Properties

1. Dispositive zinc exhibits paramagnetism due to loss of two electrons from 3d-orbital of neutral atom. (JEE 1987)

False.

Reason: Zn²⁺ exhibits diamagnetism. Formation of the ion involves loss of two electrons from 4s orbital. The resultant configuration of 10 electrons in 3d orbital does not have unpaired electrons. So it exhibits diamagnetism.

2. In Group IA of alkali metals, the ionization potential decreases down the group. Therefore lithium is a poor reducing agent.

False

Reducing strength is determined by the negative of reduction potential (i.e., oxidation potential) and not by the ionization potential. Lithium is the strongest reducing agent among alkali metals.

3. Both potassium ferrocyanide and potassium ferricyanide are diamagnetic. (JEE 1989)

False

Potassium ferrocyanide is diamagnetic (no unpaired electron) while potassium ferricyanide is paramagnetic (one unpaired electron)

4. The presence of polar bonds in a polyatomic molecule suggests that the molecule has non-zero dipole moment. (JEE 1990)

False

There are polyatomic molecules with polar bonds that have zero dipole moment due to symmetric arrangement of polar bonds.

5. The decreasing order of electron affinity of F,Cl, Br is F>Cl>Br. (JEE 1993)

False

The order is Cl>F>Br. Due to the small size in F atom there is larger electronic repulsion. Hence electron affinity is more in Cl than in F.


6. The basic nature of hydroxides of Group13 (Gr. III B) decreases progressively down the group. (JEE 1993)

False

Basic nature increases as the element becomes more metallic. As one goes down the group metallic character increases.