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

When Al is added to the 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

CO₂ and N₂ are non-supporters of combustion. However, for putting out fires CO₂ is preferred over N₂ because CO₂:

1. Does not burn.

2. Forms non-combustible products with burning substances.

3. Is denser than nitrogen.

4. Is a more reactive gas.

When sodium or potassium oxide is heated in a current of $C{O}_2 at 360°C$, 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

Which is a true acid anhydride?

(1) $A{l}_2{O}_3$

(2) CO

(3) CaO

(4) $C{O}_2$