A pair among the following that have the same size is:
1. Fe2+, Ni2+
2. Zr4+, Ti4+
3. Zr4+ , Hf4+
4. Zn2+, Hf4+
Which of the following species is colourless?
1. and
2. Cu2Cl2 and
3. and Cu2Cl2
4. and
Among the following, the incorrect statement regarding interstitial compounds is:
1. They retain metallic conductivity.
2. They are chemically reactive.
3. They are much harder than the pure metal.
4. They have higher melting points than the pure metal.
A diamagnetic lanthanoid ion among the following is :
(At. numbers: Ce = 58, Sm = 62, Eu = 63, Yb = 70)
1. Ce2+
2. Eu2+
3. Sm2+
4. Yb2+
The reason for lanthanoid contraction is:
1. Negligible screening effect of 'f' orbitals
2. Increasing nuclear charge
3. Decreasing nuclear charge
4. Decreasing screening effect
From the following, which is the most basic hydroxide?
1. Ce(OH)3
2. Lu(OH)3
3. Yb(OH)3
4. Tb(OH)3
Actinide contraction is
mainly related to:
1. Poor shielding by 5f subshell
2. Extraordinary decrement in Zeff
3. Both (1) and (2)
4. Strong shielding by 5f subshel
When iron becomes passive by "X", it is due to the formation of "Y". X and Y, respectively, are:
1. Dil. HCl,
2. 80% Conc. ,
3. Conc. ,
4. Conc. HCl,
When KMnO4 solution is added to hot oxalic acid solution, the decolorization is slow in the beginning but becomes instantaneous after some time. This is because :
1. acts as auto catalyst.
2. is formed.
3. Reaction is exothermic.
4. catalyses the reaction.
Which of the following statements is false?
1. | MnO2 dissolves in conc. HCl, but does not form Mn4+ ions. |
2. | oxidizes hot concentrated liberating oxygen. |
3. | is formed when infused KOH is oxidized by air, , or |
4. | The decomposition of acidic is not catalyzed by sunlight. |