Which alkali metal has the lowest melting point and exists as a liquid at 30 degree temp–
(1) Na
(2) K
(3) Rb
(4) Cs
The boiling point of calcium is abnormally high as compared to magnesium because-
1. In calcium d-orbital forms a weak metallic bond
2. In calcium p-orbital forms a weak metallic bond
3. In calcium d-orbital forms a strong metallic bond
4. In calcium s-orbital forms a strong metallic bond
The decreasing order of II ionisation energy of K, Ca, and Ba is –
(1) K > Ca > Ba
(2) Ca > Ba > K
(3) Ba > K > Ca
(4) K > Ba > Ca
Two metals X and Y form covalent halides. Both halides can act as Lewis acids and a catalyst in Friedel Crafts reaction. Halide of X is polymer in the solid state and a dimer in the vapour state which decomposes to monomer at 1200 K. However, halide of Y is a dimer in vapour state and becomes ionic in polar solvent. X and Y are respectively.
(1) Be, Al
(2) Al, Be
(3) Be, Ca
(4) Mg, Ca
Which of the following compounds decomposes on heating similar to .
(1)
(2)
(3)
(4) All
Solubility of sulphates in water decreases from to . It is due to the fact that –
(1) Ionic nature increases
(2) Size of ion increases
(3) Lattice energy decrease
(4) Hydration enthalpy of ions decreases
In the Solvay process of manufacture of sodium carbonate, the raw materials used are :
1. Aqueous NaOH, and
2. Molten NaOH, and CO
3. Brine NaCl, and CO
4. Brine NaCl, and
A blue coluored solution of an alkali metal in liq NH3 is due to the presence of -
1. atoms.
2. ions .
3. Solvated anions .
4. Solvated electrons.
Alkali metal ions are-
1. Diamagnetic and coloured.
2. Diamagnetic and colourless.
3. Paramagnetic and coloured.
4. Paramagnetic and colourless.
A compound X on heating gives a colourless gas. The residue is dissolved in water to obtain Y. Excess is bubbled through an aqueous solution of Y, and Z is formed. Z on gentle heating gives back X. The compound X is-
1.
2.
3.
4.