Question

Out of the following, which one is not an example of a solution?
Options-
A.Air
B.Brass
C.Amalgam
D.Benzene in water

Answer 1

Hint: Solution is described as a homogenous mixture which is composed of two or more substances whose composition may change but within the accepted limits. In the case of homogeneous mixture composition and different properties of solution it remains constant while it may vary in heterogeneity.

Complete answer:
Any kind of solution is made up of two basic components which are solute and solvent. Solute is always present in smaller quantities as compared to solvent which is in large quantities.
Air is composed of basically two components solute and solvent. As we know that air is a mixture of a large number of gases in different proportions like carbon, oxygen, nitrogen, argon, carbon monoxide and many more. Therefore, a mixture of any specific two gases will act as a solution like a mixture of nitrogen with oxygen in definite proportion as a solution in which one gas acts as solute while other as a solvent.
Brass is a type of alloy which is composed of two different metals. Main constituent of brass is copper and zinc in a specific proportion. Brass is prepared by adding a solution of copper in a molten zinc. Brass may also contain small quantities of other metals like silicon, magnesium, aluminium etc. all the components in brass are completely mixed with each other to form a solution. Therefore, constituents of brass are not easily separated.
Amalgam is a type of alloy which is composed of mercury metals along with some other metals like iron, tungsten, platinum. Amalgam can exist either in solid, liquid or solid paste. Amalgam is basically used during the mining of gold and silver metals. Amalgams are a type of solid solution in which two solids are mixed to form a solution.
Benzene is an organic compound and it is non-polar in nature. According to the law of “like dissolve like”, benzene has a tendency to get dissolved in any non-polar solvent like hexane, chloroform and many more. As we know water is a polar solvent so benzene does not dissolve completely in water and does not form a solution.
$ \Rightarrow $ Benzene in water is not an example of a solution.

Hence option $\left( B \right)$ is the correct option.

Note:
There are various types of solution like gaseous solution in which two gaseous components are mixed with each other for example- oxygen mixed with nitrogen. Liquid solution in which two liquid components are mixed like salt in water.