Acid and Alkali

A sample X has characteristics such as sour taste, changes litmus paper from blue to red and has pH of below 7. What can sample X be?

• lemon juice

• sodium hydroxide

• honey

• tooth paste

Keisha carried out an experiment on sample M and N.

Sample M turns litmus paper blue to red; has pH 3.

Sample N turns litmus paper red to blue; has pH 12.

Identify sample M and N

• M - Orange; N - vinegar

• M - Hydrochloric acid; N - Nitric acid

• M - Ammonia; N- Soap

• M - Sulphuric acid; N - Ammonia

Fish can survive only in lake water that is neutral. A group of students tested a sample of water from a lake using pH scale. Which of the following will give the correct colour?

• blue

• green

• yellow

• red

Which indicator will change from blue to red or vice versa when tested with acid or alkali?

• pH paper

• pH indicator

• litmus paper

• universal indicator

which of the following are examples of acid? you may tick more than 1

• Hydrochloric acid

• potassium hydroxide

• vinegar

• nitric acid

• ammonia

Which of the following are examples of alkali? you may tick more than 1

• Ammonia

• Citric acid

• fertilizer

• potassium hydroxide

• car battery

__________________ is a chemical reaction between an acid and an alkali.

products of reaction between acid and alkali are

calcium hydroxide reacts with hydrochloric acid to form ?

• calcium nitrate + water

• calcium chloride + hydrogen

• calcium sulfate + water

• calcium chloride + water

How do you test for the presence of acid in the reaction?

• use lime water

• use burning splint

• use litmus paper

• use glowing splint