Lesson 8 CSI

• Acids and alkalis

Acids and Alkalis

Success Criteria Level 5 - Identify a solution as acid or alkali using an indicator Level 4 - Give examples of indicators that can be used to classify acids and alkalis.Level 4 - Record your results on a tableLevel 3 - Recognise common hazard symbols. Level 3 - Be able to name some common acids

Learning objective – To be able to distinguish between acids and alkalis

Corrosive

flammable

irritant

poisonous/toxic

Match the meaning to the hazard symbol

Names of acids

Names of acids

Citric Hydrochloric

Nitric

Sulphuric

Vinegar

Ethanoic acid

Phosphoric acid

Some common acids

Three acids are particularly common in the laboratory .

These are strong acids that should be treated with the greatest respect.

Acid Formula

hydrochloric HCl

sulphuric H2SO4

nitric HNO3

Indicators: acid or alkali?

An indicator is a dye which changes colour according to whether it is in an acidic or alkaline solution.

Litmus is an indicator that is red in acid and blue in alkali.

Litmus Test

Substance Colour change with red litmus

Colour change with blue litmus

Acid or alkali

A

B

C

Testing using litmus