Mixture of salt and water is a solution while that of oil and water is not. Explain.

A mixture of alcohol and water is called a true solution while that of mustard oil and water is known as emulsion. How will you account for it ?

A mixture of salt and water can be separated by

A mixture of oil and water is separated by:

In the mixture of salt and water , salt is 5% .If 20 liter of water get evaporated then salt become 15% then find initial quantity of mixture ?

The salt that forms neutral solution in water is