Acid/Base and Reactions

Acid/Base and Reactions

Year 10 Chemistry

​What we will learn about

• ​definition of acids and bases

• ​pH scale

• ​indicators

• ​neutralisation reactions

  • ​acid+ base

  • ​acid + carbonate

​Definition of an acid

• pH less than 7

• ​turns blue litmus paper red

• ​often sour

• ​produces H+ ions in solution

Multiple Choice

Select the name of the following acid: HCl

• Hydrochloric acid

• Chlorous acid

• Chloric acid

​Definition of a base

• ​pH greater than 7

• ​turns red litmus paper blue

• ​often bitter

• ​produces OH+ ions in solution

​pH scale

• ​used to measure the acidity or basicity of a substance

• ​takes the negative logarithmic value of H+ ions OR substances with more H+ ions will ne lower on the pH scale

• ​Therefore, acids are low on the pH scale, and bases are high

Multiple Choice

Scale that measures how acidic or basic something is.

• aH

• bH

• pH

• Hp

Multiple Choice

Which pH is considered neutral?

• 1

• 3

• 7

• 14

Multiple Choice

The table shows the pH of several solutions. Which solution is the most acidic?

• vinegar

• milk

• water

• bleach

Multiple Choice

According to the pH range which substance is more acidic than lemon juice

• Hydrochloric acid

• cabbage

• milk

​pH indicators

• ​we use pH indicators to test the pH of substances

• ​their colour will change depending on the pH

• ​gives a visual indicator, numerical pH values are given by technology

• ​universal indicator is the most common

​Acid + Base reactions

​Acid + Base reactions

• ​acid + base --> salt + water

• ​neutralisation reaction

• ​not always the case, but for now this is a good general equation

• ​since you know the products, all you have to do is balance

​Acid + carbonate reactions

​Acid + carbonate reactions

• ​acid + carbonate --> salt + water + carbon dioxide

• ​again, a neutralisation

• ​often used to see whether a substance is acidic

• ​heating carbonates always decomposes the carbonate into its metal oxide + carbon dioxide

  • ​metal carbonate + heat --> metal oxide + CO₂

Multiple Choice

Which salt will be produced if magnesium react with hydrochloric acid?

• Magnesium oxide

• Magnesium sulfate

• Magnesium sulfide

• Magnesium chloride

Multiple Choice

A neutralisation reaction is a reaction between 

• Acid and a Base 

• Acid and water 

• Base and water 

• None of the above 

Multiple Choice

Complete the following reaction: Sulphuric acid + sodium carbonate --> 

• Carbon dioxide + water 

• calcium carbonate + water + carbon dioxide 

• Sodium sulphate + water + carbon dioxide 

• Sodium chloride + water + carbon dioxide