Acid Base Theories

Acid/Base and Reactions

Year 19 Chemistry

​What we will learn about

• ​review of acids and bases

• ​pH scale

• ​indicators

• ​discuss results of neutralisation reactions

  • ​acid+ base

​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

Multiple Choice

Which of the following is true .

• Acids and bases form hydroxide ions in solution

• Acids form hydroxide ions and bases hydrogen ions in solution

• Acids form hydrogen ions in solution, bases do not form ions in solution

• Acids form hydrogen ions in solution and bases hydroxide ions

​pH scale

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

• ​

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

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

​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

• The universal indicator is a mix of many different indicators. It is useful for not only determining whether a substance is an acid or base, but how basic or acidic it is.

• As previously mentioned, the universal indicator is measured by the pH scale. 

Multiple Choice

Examine the results (color change) of the pH paper shown in the picture.  What type of substance was tested?

• an acid

• a base

• a neutral substance

• none of the above

​Acid + Base reactions

• ​acid + base --> salt + water

• ​neutralisation reaction

• The name of the salt is determined by the salt and metal ions that created them.

1. Describe what happened to the pH as you gradually added more and more base.
2. Identify the type of reaction that you carried out in this experiment.
3. Write a word equation for the reaction that you investigated.

​Discussion Questions (from practical)

Marko investigated the reaction between an acid and base. The acid was Hydrochloric acid and the base was Sodium Hydroxide

1. Complete the word equation below. (Salt and Water is produced)

Hydrochloric acid + Lithium Hydroxide ->

2. Write the BALANCED chemical equation if you finish early. (Hydroxide Ion is OH^-)

Example

​Red is Metal

Blue is Acid.

Acid and Base Reaction

1. Hydrochloric acid + Lithium Hydroxide --> Lithium Chloride + Water

2. HCl + LiOH --> LiCl + H2O

    

Complete now
( Also available on one note / Seqta.)

1. Outline the role of Universal Indicator in Neutralisation reactions (or any!)

2. Complete Lab Assessment Discussion Questions (one note)

3. Complete revision worksheets for validation tomorrow.

4. Quizizz Mega revision.

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