Aluminium metal is corroded in coastal places near to the sea, because protective oxide film:
(1) is removed by sea water
(2) reacts with sea water
(3) is attacked by salts present in sea water
(4) reacts with sand particles
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. 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 , 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
(3)
(4)