Ks3 chemistry
This presentation is the property of its rightful owner.
Sponsored Links
1 / 34

KS3 Chemistry PowerPoint PPT Presentation


  • 92 Views
  • Uploaded on
  • Presentation posted in: General

KS3 Chemistry. 7E Acids and Alkalis. Contents. 7E Acids and Alkalis. What are acids and alkalis?. Hazard symbols. Indicators and the pH scale. Neutralization. Summary activities. What is an acid?. Acids are a group of chemicals.

Download Presentation

KS3 Chemistry

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Ks3 chemistry

KS3 Chemistry

7EAcidsandAlkalis


Contents

Contents

7E Acids and Alkalis

What are acids and alkalis?

Hazard symbols

Indicators and the pH scale

Neutralization

Summaryactivities


What is an acid

What is an acid?

Acids are a group of chemicals.

What do you know about acids? Are all acids dangerous?


What is an acid1

What is an acid?

Acids are a group of chemicals.

Which of these items contains an acid?

laboratory acids

everyday acids

Can you think of other examples of acids?


What is a weak acid

What is a weak acid?

Acids are found in household items such as food, drink

and beauty/skincare products.

It is safe to handle these acids and even taste them, if they

are for eating! These acids are known weak acids.


What is a strong acid

What is a strong acid?

Some acids, like those found in the laboratory or a car

battery, are very dangerous (too dangerous to taste or touch).

These acids are said to be corrosive as they can damage

other materials by wearing them away!They are strong acids.

Why must strong acids always be handled very carefully?


What is an alkali

What is an alkali?

Alkalis are another group of chemicals, the opposite of acids.

Which of these items contains an alkali?

everyday alkalis

laboratory alkalis

Can you think of other examples of alkalis?


What is a weak alkali

What is a weak alkali?

Alkalis are found in soaps and other materials used for cleaning.

It is safe to handle these alkalis, which can feel soapy.

These alkalis are known as weak alkalis.


What is a strong alkali

What is a strong alkali?

Some alkalis, like those in the laboratory or in cleaning

materials such as toilet cleaner, are too dangerous to touch.

These alkalis are said to be caustic because they can burn skin and damage other materials! They are strong alkalis.

Why must strong alkalis always be handled very carefully?


Contents1

Contents

7E Acids and Alkalis

What are acids and alkalis?

Hazard symbols

Indicators and the pH scale

Neutralization

Summaryactivities


What are hazard symbols

What are hazard symbols?

How can you tell which chemicals are safe and which are dangerous?

Special symbols are used on bottles and vehicles that

contain dangerous chemicals.

corrosive

toxic

irritant

harmful

highly flammable

These hazard symbols show why the chemical is dangerous.

Why is it important that these symbols can be recognised by

people from other countries?


What do hazard symbols mean

What do hazard symbols mean?


Contents2

Contents

7E Acids and Alkalis

What are acids and alkalis?

Hazard symbols

Indicators and the pH scale

Neutralization

Summaryactivities


What is an indicator

What is an indicator?

How can you test a liquid to find if it is an acid or an alkali?

An indicator is a special chemical that changes

to a different colour in an acid or an alkali.

Litmus paper and litmus solution are examples of indicators.

Litmus is red in acid.

Litmus is

blue in alkali.


Litmus test experiment

Litmus test experiment


What is universal indicator

What is universal indicator?

Litmus is used to show if a solution is acid or alkali.

Litmus does not show if the acid or alkali is weak or strong.

Universal indicator has a range of colours that show how weak or strong the acid or alkali is.

strongeracid

stronger alkali

strongacid

weak alkali

weakacid

strongalkali

neutral

What is the colour for a weak acid?

What is the colour for a strong alkali?


What is the ph scale

What is the pH scale?

The strength of an acid or alkali is measured by the pH scale.

Each universal indicatorcolour is given a number called the pH value.

Universal indicator can tell you the pH of a solution.

strongeracid

stronger alkali

1 2 3 4 5 6 7 8 9 10 1112 1314

strongacid

weak alkali

weakacid

strongalkali

neutral

What is the pH of a weak acid?

What is the pH of strong alkali?


What is the ph

What is the pH?


What type of substance

Are these substances acidic or alkaline?

Are they weak or strong?

What type of substance?

1

2

3

4

5

6

7

8

9

10

11

12

13

14

acid

alkali

very weak acid

very strong acid

very weak alkali

weak alkali

strong acid

very strong alkali

weak acid


Contents3

Contents

7E Acids and Alkalis

What are acids and alkalis?

Hazard symbols

Indicators and the pH scale

Neutralization

Summaryactivities


Mixing an acid and an alkali

Mixing an acid and an alkali

What happens when an acid and an alkali are mixed?

?

Mixing an acid and an alkali causes a chemical change.

This chemical change is called a chemical reaction.

How do you know this chemical reaction has taken place?


What is neutralization

What is neutralization?

The chemical reaction betweenan acidandan alkali

is calledneutralization.

acid

alkali

a salt

water

What happens to the pH value of the reaction mixture during neutralization?

The pH value of the reaction mixture becomes closer to 7.


What is neutralization1

What is neutralization?

The chemical reaction between anan acidandan alkalican be written as:

acid

alkali

a salt

water

What are the two new substances produced by a neutralization reaction?


Neutralization and indigestion

Neutralization and indigestion


Neutralizing stings

Neutralizing stings

A beesting

isacidic.

A wasp sting

isalkaline.

Why can bicarbonate of soda (pH 9) be used to treat a bee sting?

Why can vinegar (pH 3)

be used to treat

a wasp sting?


Neutralizing soil

Neutralizing soil

Soils in different places can be acidic, alkaline or neutral.

Many plants do not grow

well in acidic soil.

Why do farmers test soil

to check the pH?

Farmers often add an alkali to acidic soil to make their plants grow better.

How does the alkali help to treat the acidic soil?


Neutralizing acid rain

Neutralizing acid rain

Gases emitted by cars, power stations and factories mix with rainwater in the atmosphere.

This rainwater has a pH <5.5.

Why is it called acid rain?

Acid rain can have a harmful effect on the environment killing trees, polluting lakes and damaging buildings.

How can the effects of

acid rain be prevented?


Contents4

Contents

7E Acids and Alkalis

What are acids and alkalis?

Hazard symbols

Indicators and the pH scale

Neutralization

Summary activities


Glossary

Glossary

  • acid –A chemical that has a pH less than 7.

  • alkali –A chemical that has a pH greater than 7 and dissolves in water.

  • indicator –A special chemical that changes into different colours in acid and alkali solutions.

  • neutral –A chemical with a pH of 7 that is not an acid or an alkali.

  • neutralization –The chemical reaction between an acid and an alkali.

  • pH scale – The range of values that shows how strong or weak an acid or alkali is.

  • universal indicator – The indicator that shows the pH value of a chemical.


Anagrams

Anagrams


Word search

Word search


Facts about acids

Weak acids, like lemon juice and vinegar, taste sour.

Strong acids are corrosive and can “eat away” at metal,

stone and flesh!

Acids turns blue litmus paper red.

Acids have a pH of less than 7.

Acids can be neutralized with alkalis.

Facts about acids


Facts about alkalis

Alkalis feel soapy and are used in household cleaning

materials.

Strong alkalis are caustic.

Alkalis turn red litmus paper blue.

Alkalis have a pH of more than 7.

Alkalis can be neutralized with acids.

Facts about alkalis


Multiple choice quiz

Multiple-choice quiz


  • Login