Practice MCQ Questions and answers on Chemistry-GK

Hydrogen is not a noble gas as it has one electron in its shell and it is not stable unlike noble gases which are having 2,8,8 electrons in their outer shell.

Milk is a mixture.

Mixture can be homogeneous and heterogeneous.

Oxygen helps in burning.

Bromine is the other metal that is liquid at standard conditions for temperature and pressure.

In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid and as a base. Many metals (such as copper, zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Amphoterism depends on the oxidation states of the oxide.

Sublimation apparatus is a piece of laboratory glassware used in the technique of sublimation usually used by chemists to purify compounds. Typically a solid is placed in a vessel which is then heated under vacuum. Under this reduced pressure the solid volatilizes and condenses as a purified compound on a cooled surface, leaving the non-volatile residue impurities behind. This cooled surface often takes the form of a cold finger. Once heating ceases and the vacuum is released, the sublimed compound can be collected from the cooled surface. Impure camphor is purified by this process.

The method of separation using magnets is used when one of the components is magnetic. So the heterogeneous mixture of iron filings and some other material (such as sulphur powder) can be separated by using magnets. Similarly, a mixture of sand and iron filings can be separated by magnet.

Filling a bulb with an inert gas such as argon or nitrogen slows down the evaporation of the tungsten filament compared to operating it in a vacuum.

The most abundant inert gas in the atmosphere is Argon.