Question

Two properties which can be used to determine if a substance is pure or not are its _______ point and ________ point.

• A. boiling
• B. melting

Answer 1

• A pure substance is one in which all the molecules are of the same kind. A pure substance is either an element or a compound.
• Each pure substance has its characteristic properties such as melting and boiling point.
• The melting point of pure water, at which ice changes to water is$0°\mathrm{C}$. Its boiling point at which water boils and changes to steam at sea level is$100°\mathrm{C}$.
• These values change if impurities are present in water. Hence, we can use these characteristic properties to test whether a substance is pure or not.

Therefore, two properties that can be used to determine if a substance is pure or not are its melting point and boiling point.