Point out the incorrect statement.

(1) Hardness of water depends upon its soap consuming power

(2) Temporary hardness is due to bicarbonates of calcium and magnesium

(3) Permanent hardness is due to soluble sulphates, chlorides and nitrates of Ca and Mg

(4) Permanent hardness can be removed by boiling water

Metal which does not react with cold water but evolves H₂ with steam is:

(a) Na

(b) K

(c) Pt

(d) Fe

Permutit is chemically known as:

1. Hydrated sodium aluminium silicate

2. Sodium hexa meta-phosphate

3. Sodium silicate

4. Sodium meta-aluminate

Hydrogen is not obtained when zinc reacts with:

(a) cold water

(b) dil. H₂SO₄

(c) dil HCl

(d) hot 20% NaOH

Hydrogen peroxide is now generally prepared on industrial scale by the:

(1) Action of H₂SO₄ on barium peroxide

(2) Action of H₂SO₄ on sodium paraoxide

(3) Electrolysis of 50% H₂SO₄

(4) Burning hydrogen in excess of oxygen

Ionic hybrides are formed by:

(1) transition metals

(2) elements of very high electropositivity

(3) elements of very low electropositivity

(4) metalloids

Very pure hydrogen (99.9%) can be made by which of the following processes ?

(1) Mixing natural hydrocarbons of high molecular weight

(2) Electrolysis of water

(3) Reaction of salt like hydrides with water

(4) Reaction of methane with steam

Para hydrogen is-

1. Less stable than ortho hydrogen.

2. More stable than ortho hydrogen.

3. As stable as ortho hydrogen.

4. None of the above.

Hydrogen combines directly with:

(a) Ca

(b) Cu

(c) Zn

(d) Fe

Acidified solution of chromic acid on treatement with H₂O₂ yields :

(a) ${\mathrm{CrO}}_3 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$

(b) ${\mathrm{Cr}}_2{\mathrm{O}}_2 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$

(c) ${\mathrm{CrO}}_5 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{K}}_2{\mathrm{SO}}_4$

(d) ${\mathrm{H}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$