Acids, Bases, Salts, Indicators & Reactions

What is the difference between a base and an alkali?

The table below names five acid-base indicators and shows the colours seen at various pH values.

The pH values of some solutions are:

Sulphuric acid pH= 1.0

Carbonic acid pH= 5.5

Ammonia pH= 9.0

Sodium hydroxide pH= 12.0

By using the CODE letters of indicators, answer the following question.

Which indicators show the same colour in sodium hydroxide?

• A and B

• B and D

• D and E

• B and C

Tags

NGSS.MS-PS1-2

What is the colour of methyl orange in an acid?

• Red

• Yellow

• Orange

• Colourless

Which of the following is a neutral substance?

• Hydrochloric acid

• Lemon juice

• Ammonia

• Sodium chloride solution

Give another name for lime water.

• Potassium oxide

• Calcium oxide

• Calcium hydroxide

• Sodium hydroxide

Which of the following pH is strongly acidic?

• 5.0

• 9.5

• 2.0

• 13.4

Give the products formed when Zinc reacts with Hydrochloric acid?

• Zinc and Hydrogen gas

• Zinc chloride and Oxygen

• Zinc chloride and Hydrogen gas

• Zinc and salt

Tags

NGSS.MS-PS1-5

Which of the following is most likely to be basic?

• Orange juice

• Laundry detergent

• Vinegar

• Coke

Human blood has a pH between 7.35 and 7.45. Which of the following best describes human blood?

• Strongly acidic

• Strongly basic

• slightly acidic

• slightly basic

Tags

NGSS.HS-LS1-3

What is the colour of blue litmus in an acid?

• Pink

• Red

• Purple

• Colourless