Question

Which of the following pair of substances contains only base?

• A. Vinegar and lemon
• B. Limewater and curd
• C. Soap and toothpaste
• D. Apple and tamarind

Answer 1

The correct option is C Soap and toothpaste

Acids are sour in taste and bases are bitter in taste. The table given below shows few substances and the acid or base present in them. $$\begin{array}{ccc}\text{Substance}& \text{Contains}& \text{Nature of the substance}\\ \text{Vinegar}& \text{Acetic acid}& \text{Acidic}\\ \text{Lemon}& \text{Citric acid}& \text{Acidic}\\ \text{Curd}& \text{Lactic acid}& \text{Acidic}\\ \text{Apple}& \text{Malic acid}& \text{Acidic}\\ \text{Tamarind}& \text{Tartaric acid}& \text{Acidic}\\ \text{Soap}& \text{Sodium hydroxide}& \text{Basic}\\ \text{Toothpaste}& \text{Sodium fluoride}& \text{Basic}\end{array}$$ So the pair of soap and toothpaste contain only bases.