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

Which is a true acid anhydride?

(1) $A{l}_2{O}_3$

(2) CO

(3) CaO

(4) $C{O}_2$

$$Which of the following best explains the difference in hydrolytic behaviour between CCl₄ and SiCl₄?

1.  Carbon cannot expand its octet but silicon can expand.

2. The electronegativity of carbon is higher than that of silicon

3. The ionization potential of carbon is higher than that of silicon

4.  Carbon forms double and triple bonds, but silicon does not