Aluminium deposited as vapours on glass forms a good mirror, essentially because:

(1) it has better shine than Ag

(2) it does not scratch

(3) coating is much smoother

(4) it does not tarnish in air

Conc. $HN{O}_3$ can be stored in a container of:

(1) Cu

(2) Al

(3) Zn

(4) Sn

Duralumin is an alloy of:

(1) Al and Mg

(2) Mg and Cu

(3) Al, Mg, Mn and Cu

(4) Al and Cu

Aluminium is not used:

(1) In thermite welding

(2) As oxidiser in metallurgy

(3) For making utensils

(4) In silvery paints

What happens when aluminium is added to an aqueous potassium hydroxide solution?

1. No reaction takes place 

2. Oxygen gas is evolved

3. Water is produced 

4. Hydrogen gas is evolved

A metal powder if spread in air, becomes hazardous is-

(1) Al 

(2) B

(3) Ca

(4) K

Why is CO₂ more effective than N₂ in extinguishing fires?

1. It is non-combustible.

2. It forms non-combustible products with burning substances.

3. It has a higher density than nitrogen.

4. It is chemically more reactive than nitrogen.

When sodium or potassium oxide is heated in a current of $C{O}_2<mspace\; width="1em"></mspace>at<mspace\; width="1em"></mspace>360°C$, we get:

1. sodium formate

2. sodium oxalate

3. sodium acetate

4. sodium carbonate

Which can be directly brought into gaseous state from solid state?

(1) CO

(2) Solid $C{O}_2$

(3) $P{H}_3$

(4) $CO+H_2$

Which is amphoteric oxide?

1. ZnO

2. MnO^-₄

3. CO₂

4. SiO