The chemical formula of Plaster of Paris is:
1.
2.
3.
4. 3CaSO4.H2O
Alkali metal with the lowest melting point is -
1. Na
2. K
3. Rb
4. Cs
An alkali metals that forms only the normal oxide M2O on heating in air is-
1. Rb
2. K
3. Li
4. Na
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
The correct order of thermal stability of carbonates of Group 2 elements is-
1.
2.
3.
4.
The incorrect statement among the following is-
1. Sodium metal is used in organic qualitative analysis.
2. Sodium carbonate is soluble in water and it is used in inorganic qualitative analysis.
3. Potassium carbonate can be prepared by the solvay process.
4. Aq. solution of potassium bicarbonate is a weak base.
The incorrect statement among the following is -
1. Li+ has minimum degree of hydration among alkali metal cations.
2. The oxidation state of K in KO2 is +1
3. Sodium is used to make Na / Pb alloy.
4. MgSO4 is readily soluble in water.
The correct order of increasing thermal stability of K2CO3, MgCO3, CaCO3 and BeCO3 is :
1.
2.
3.
4.
An amphoteric hydroxide among the following is :
1.
2.
3.
4.