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) $C{O}_2$

$CC{l}_4$ does not show hydrolysis but $SiC{l}_4$ is readily hydrolysed because:

(1) carbon cannot expand its octet but silicon can expand.

(2) electronegativity of carbon is higher than of silicon

(3) IP of carbon is higher than of silicon

(4) carbon forms double and triple bonds but not silicon