Question

Oil and water are miscible liquids.
a.) True
b.) False

Answer 1

Hint: There is a very simple concept - Like dissolves like. The two liquids which would be similar to each other in property would get easily dissolved. The liquids are classified into two types - Polar and nonpolar. The polar ones are miscible with polar liquids while the non-polar liquids dissolve in nonpolar ones. The oil is nonpolar and water is a polar liquid.

Complete answer:
First, let us see what miscibility is and what miscible liquids are. The miscibility means the property to completely dissolve. The two or more liquids which can completely dissolve into each other without showing separate layers are miscible liquids. Everyone one knows what dissolves like. This means that polar groups get dissolved in polar while the non-polar liquids dissolve well in nonpolar liquids.
In simple language, we can say that the liquids which are hydrophilic i.e. water loving are miscible in hydrophilic liquids while the hydrophobic liquids i.e. water repelling liquids are miscible in hydrophobic liquids.
If we see the question, the oil is hydrophobic in nature. It is non polar while the water is polar. Thus, oil and water can not completely dissolve. So, they are not miscible.

Thus, the statement is false.

Note: It must be noted that the liquids that can not completely dissolve are called immiscible liquids. Such liquids which do not completely dissolve in each other form separate layers while the completely dissolving liquids form a uniform solution.