The property of alkali metals that increases with increasing atomic number is -
1. First ionization energy
3. Hydration energy of the univalent ion
4. Atomic radius
An amphoteric oxide among the following is-
Potassium is kept-
1. Under cold water.
2. In ammonia.
3. In alcohol.
4. In kerosene.
A colourless salt among the following that gives violet colour to Bunsen flame is -
The polarising power of Mg is close to that of –
The incorrect statement among the following regarding Lithium is that-
1. The hydroxide, carbonate and nitrate decompose to give the oxide on heating.
2. It is the most electronegative element of group IA.
3. The hydrogen carbonate cannot be isolated as a stable solid.
4. It forms superoxide.
The reason for a lower basicity of hydroxides of alkaline earth metals than alkali metals is :
1. Alkali metals form ionic compounds.
2. The bond strength of oxygen is more for alkali metals.
3. The electropositivity of alkali metals is more than alkaline earth metals.
4. The electropositivity of alkali metals is less than alkaline earth metals.
Lithium has the minimum tendency to form ion. The aqueous solution of lithium is the
1. Strongest reducing agent.
2. Poorest reducing agent.
3. Strongest oxidising agent.
4. Poorest oxidising agent.
The strongest factor responsible for reducing action of Li metal in an aqueous solution is :
1. Sublimation enthalpy .
2. Ionisation enthalpy.
3. Hydration enthalpy .
4. Electron-gain enthalpy.
A compound soluble in pyridine is:-