Acids and Alkalis

Question 1

What can solutions be?

Answer 1

Acidic, alkaline or neutral

Question 2

Pure water is…

Answer 2

Neutral

Question 3

What are two acids found at home?

Answer 3

Vinegar and Lemon Juice

Question 4

What are two acids found in the lab?

Answer 4

Sulfuric acid and Hydrochloric acid

Question 5

What are three alkalis found at home?

Answer 5

Baking soda, bleach and indigestion tablets

Question 6

What are some alkalis found in the lab?

Answer 6

Sodium hydroxide and calcium hydroxide

Question 7

If a substance has the word hydroxide in its name, what is it?

Answer 7

an alkali e.g potassium hydroxide

Question 8

What can indicators be used to find out?

Answer 8

Whether a solution is acidic, alkaline or neutral by the colour they turn.

Question 9

What can plant extracts be used as?

Answer 9

Indicators e.g red cabbage is a different colour in different solutions

Question 10

What are universal indicator and pH paper?

Answer 10

Indicators

Question 11

When does universal indicator and pH paper turn red?

Answer 11

In acidic solutions

Question 12

What colour does universal indicator and pH paper turn in neutral solutions?

Answer 12

Green

Question 13

When does universal indicator and pH paper turn blue?

Answer 13

In alkaline solutions

Question 14

What can universal indicator/pH paper be used to find?

Answer 14

the pH of a solution

Question 15

What does the pH scale measure?

Answer 15

how acidic or alkaline a solution is

Question 16

The pH scale is a numbered scale going from 0 to…

Answer 16

14

Question 17

What number is an acid on the pH scale?

Answer 17

pH=less than 7

Question 18

What number is neutral on the pH scale?

Answer 18

pH=7

Question 19

What number is an alkali on the pH scale?

Answer 19

pH=grater than 7

Question 20

What pH value do very acidic solutions have?

Answer 20

the range from 0-2

Question 21

What pH value do weakly acidic solutions have?

Answer 21

the range from 3-6

Question 22

What pH value do very alkaline solutions have?

Answer 22

the range from 12-14

Question 23

What pH value do weakly alkaline solutions have?

Answer 23

the range from 8-11

Question 24

What does burning fossil fuels produce?

Answer 24

Carbon Dioxide

Question 25

When an acid and alkali react with each other in equal volumes what happens?

Answer 25

they are neutralised and form a solution with pH=7

Question 26

What happens when hydrochloric acid is neutralised using sodium hydroxide?

Answer 26

Sodium chloride (table salt) is made

Question 27

How can solid salt be obtained?

Answer 27

by evaporating the salt solution

Question 28

What is a use of neutralisation?

Answer 28

Indigestion (too much stomach acid) can be neutralised using magnesium hydroxide (milk of magnesia)

Question 29

What is a use of neutralisation?

Answer 29

Wasp stings are alkaline and can be neutralised by using vinegar (acidic)

Question 30

What is a use of neutralisation?

Answer 30

Bee stings are acidic and can be neutralised by using sodium bicarbonate (alkali) - acid soils an be treated with the alkali calcium hydroxide (known as lime).

Question 31

What word equation can represent the neutralisation reaction between an acid and alkali?

Answer 31

acid+alkali ⇾ salt + water

Question 32

What is an example of this reaction? (acid+alkali ⇾ salt + water)

Answer 32

Hydrochloric acid + sodium hydroxide⇾ sodium chloride + water

Question 33

How can this word equation be represented in a symbol equation?

Answer 33

HCI + NaOH ⇾ NaCI + H2O

Question 34

There are many different salts. Where does the metal part of the salt come from?

Answer 34

The alkali

Question 35

Where does the non-metal part of the salt comes from?

Answer 35

the acid

Question 36

What is a salt?

Answer 36

A compound made up of a metal and a non-metal part.

Question 37

Describe the structure of an atom

Answer 37

An atom has a nucleus that contains protons and neutrons and the nucleus is surrounded by electrons in different shells.

Question 38

How do you know the number of electrons in an atom?

Answer 38

the same number of protons (number of protons=number of electrons)

Question 39

How can you find the number of neutrons in an atom?

Answer 39

the atomic mass - atomic number

Question 40

What is a controlled variable?

Answer 40

The one that doesn't change

Question 41

What is an independent variable?

Answer 41

The one that is changed

Question 42

What is a dependent variable?

Answer 42

The one that is measured