Be and Mg did not give flame colour because:
1. Energy released by excited electron falls in visible region.
2. Energy released by excited electron does not fall in visible region
3. s-s transition.
4. Charge transfer.
The correct statement(s) about the structure of BeCl2 is -
a. BeCl2 (solid)- exists as polymer.
b. BeCl2 (vapour)- exists as chlorobridged dimer.
c. BeCl2 has bent structure in the vapour phase.
1. a
2. a & b
3. b
4. b & c
An alkali metals that forms only the normal oxide M2O on heating in air is-
1. Rb
2. K
3. Li
4. Na
Alkali metal with the lowest melting point is -
1. Na
2. K
3. Rb
4. Cs
The chemical formula of Plaster of Paris is:
1.
2.
3.
4. 3CaSO4.H2O
The correct order of thermal stability of carbonates of Group 2 elements is-
1.
2.
3.
4.
Alkali and alkaline earth metals cannot be obtained by chemical reduction method because they are the strongest :
1. Oxidizing agents.
2. Reducing agents.
3. Hydrating agents.
4. Drying agents.
Potassium carbonate cannot be prepared by the Solvay process because -
1. | Potassium carbonate is insoluble in water and does not precipitate out. |
2. | Potassium carbonate is soluble in water and does not precipitate out. |
3. | Potassium carbonate is soluble in water and does precipitate out. |
4. | Potassium carbonate is insoluble in water and does precipitate out. |
Lithium salts are generally hydrated because they have :
1. High polarizing power.
2. High ionization enthalpy.
3. High electronegativity.
4. Low polarizing power.
The incorrect statement among the following is-
1. | Ionisation enthalpy of alkaline earth metals is higher than alkali metals. |
2. | Alkaline earth metal oxides are more basic than alkali metal oxides. |
3. | Alkaline earth metal hydroxides are less basic and less stable than alkali metal hydroxides. |
4. | Solubility of Alkaline earth metals and alkali metal hydroxide increases down the group. |