Acids & Bases: 16 MCQs with answers

They turn blue litmus red

Acids turn blue litmus paper red, while bases turn red litmus blue.

They turn red litmus blue

Bases turn red litmus paper blue, while acids turn blue litmus red.

Less than 7

Acidic solutions have a pH less than 7. A pH of 7 is neutral, and greater than 7 is basic.

Greater than 7

Basic solutions have a pH greater than 7. A pH of 7 is neutral, and less than 7 is acidic.

7

A neutral solution, such as pure water, has a pH of 7.

NaCl

Common salt is sodium chloride, with the chemical formula NaCl.

Soap

Soap is basic in nature, while vinegar, lemon juice, and curd are acidic.

True

Acids have a sour taste, such as lemon juice and vinegar.

False

Bases turn red litmus paper blue. Acids turn blue litmus paper red.

Hydrochloric acid

Hydrochloric acid (HCl) is a strong acid that completely ionizes in water. Acetic acid, citric acid, and carbonic acid are weak acids.

Sodium hydroxide

Sodium hydroxide (NaOH) is a strong base that completely dissociates in water. Ammonium hydroxide and magnesium hydroxide are weak bases.

Salt and water

The reaction between an acid and a base is called neutralization, which produces salt and water.

Hydrogen

Acids react with metals to produce hydrogen gas, which burns with a pop sound.

Litmus

Litmus is a natural indicator extracted from lichens. Phenolphthalein and methyl orange are synthetic indicators.

Pink

Phenolphthalein is colorless in acidic and neutral solutions but turns pink in basic solutions.

Acetic acid

Acetic acid (CH₃COOH) is a weak acid that only partially ionizes in water. Hydrochloric, sulfuric, and nitric acids are strong acids.