Topic 4 Acids (Foundation)

Question 1

What are the particles that acids contain?

Answer 1

Hydrogen ions (H+)

Question 2

What are the particles that alkalis contain?

Answer 2

Hydroxide ions (OH-)

Question 3

What is the ionic equation for the reaction between an acid and an alkali?

Answer 3

H+ + OH- –> H₂O

Question 4

What is the formula for Hydrochloric acid?

Answer 4

HCl

Question 5

What is the formula for Sulphuric acid?

Answer 5

H₂SO₄

Question 6

What is the formula for Nitric acid?

Answer 6

HNO₃

Question 7

What is the formula for Sodium hydroxide?

Answer 7

NaOH

Question 8

What is an indicator?

Answer 8

A chemical with changes colour in acid or alkali

Question 9

What is the colour of Universal indicator in acid, neutral and alkali?

Answer 9

Red, green, purple

Question 10

What is the pH of a concentrated acid, neutral and concentrated alkali?

Answer 10

1, 7, 14

Question 11

What is the colour change of phenolphthalein in going from alkali to acid?

Answer 11

Pink to colourless

Question 12

What is the colour change of methy orange in going from alkali to acid?

Answer 12

Yellow to red

Question 13

How does the concentration of an acid effect the pH?

Answer 13

The higher the concentration the lower the pH

Question 14

How does the concentration of an alkali effect the pH?

Answer 14

The higher the concentration the higher the pH

Question 15

Give and equation to calculate the concentration of a solution in g/dm³

Answer 15

concentration = amount of substance (g) / volume (dm³)

Question 16

What is a dm³

Answer 16

1dm³ = 1000cm³ = 1Litre

Question 17

How does the concentration of hydrogen ions effect the pH?

Answer 17

The higher the concentration the lower the pH

Question 18

What type of compounds are bases ?

Answer 18

Metal oxides and hydroxides

Question 19

Give a general equation for how an acid reacts with a base

Answer 19

Acid + base –> salt + water

Question 20

What is the name of the type of reaction when a base is added to an acid?

Answer 20

neutralisation

Question 21

What is a salt?

Answer 21

An ionic compound made between a metal and a non-metal

Question 22

What type of salts does hydrochloric acid make?

Answer 22

Chlorides

Question 23

What type of salts does sulphuric acid make?

Answer 23

Sulphates

Question 24

What type of salts does nitric acid make?

Answer 24

Nitrates

Question 25

What are the 4 main state symbols and what do they mean?

Answer 25

(s) solid, (l) liquid, (g) gas, (aq) dissolved in solution

Question 26

Copper oxide is an insoluble base – what does copper oxide look like?

Answer 26

black powder

Question 27

Copper sulphate is a soluble salt – what does CuSO₄ (s) and CuSO₄ (aq) look like?

Answer 27

blue crystals and a blue solution

Question 28

Give the 3 main steps for making a soluble salt from acid and an insoluble base

Answer 28

Add excess base to the acid to neutralise it. Filter off the excess base. Evaporate the filtrate to give the salt

Question 29

Name the acid and the base that could be used to make copper sulphate

Answer 29

copper oxide and sulphuric acid

Question 30

What is an alkali ?

Answer 30

A soluble base

Question 31

Sodium hydroxide is an alkali. What ions are produced when sodium hydroxide is dissolved in water?

Answer 31

Na+ and OH-

Question 32

Sodium hydroxide is an alkali – what does NaOH (aq) look like?

Answer 32

A colourless solution

Question 33

Give the formula and state symbol for the alkali sodium hydroxide

Answer 33

NaOH (aq)

Question 34

Alkalis are bases. Give the general reaction for how an acid reacts with an alkali

Answer 34

Acid + alkali --\> salt + water

Question 35

What type of reaction occurs when an acid reacts with an alkali?

Answer 35

neutralisation

Question 36

What is the ionic equation for the reaction between an acid and an alkali?

Answer 36

H+ + OH- --\> H₂O

Question 37

What is the method called for adding an exact amount of acid to an alkali?

Answer 37

Titration

Question 38

List the main equipment used in a titration

Answer 38

Burette, pipette, conical flask, indicator

Question 39

In a titration what is the point at which the indicator changes colour?

Answer 39

End point

Question 40

What is the colour change of phenolphthalein in going from alkali to acid?

Answer 40

pink to colourless

Question 41

What is the colour change of methy orange in going from alkali to acid?

Answer 41

yellow to red

Question 42

List the main steps for making a soluble salt from an acid and an alkali using titration.

Answer 42

Pipette 25cm³ of alkali into a flask. Add a drop of indicator. Add acid from burette until it changes colour. Record the volume of alkali. Repeat again without indicator. Evaporate the solution to get the salt.

Question 43

Give the general equation for the reaction between an acid and a metal

Answer 43

acid + metal --\> salt + hydrogen

Question 44

What is the name of the type of reaction when an acid reacts with a metal?

Answer 44

neutralisation

Question 45

State two things you would see when a metal such as magnesium reacts with an acid

Answer 45

fizzing and the metal would disappear

Question 46

What is the test for hydrogen gas?

Answer 46

Add a lit splint and get a squeaky pop

Question 47

Why do different metals react differently with acids?

Answer 47

Metals have different reactivity (reactivity series)

Question 48

Why would you not prepare a salt from reaction of a group 1 metal with acid?

Answer 48

It would be too reactive / dangerous

Question 49

Why would you not make copper sulphate from the reaction of copper and sulphuric acid?

Answer 49

Copper is low in the reactivity series and would react very slowly

Question 50

Give the formula and state symbol for Hydrochloric acid?

Answer 50

HCl (aq)

Question 51

Give the formula and state symbol for Sulphuric acid?

Answer 51

H₂SO₄ (aq)

Question 52

Give the formula and state symbol for Nitric acid?

Answer 52

HNO₃ (aq)

Question 53

Give the general equation for the reaction between and acid and a metal carbonate

Answer 53

acid + carbonate --\> salt + carbon dioxide

Question 54

What is the name of the type of reaction when an acid reacts with a metal carbonate?

Answer 54

neutralisation

Question 55

State two thing you would see when a metal carbonate such as calcium carbonate reacts with an acid

Answer 55

the reaction would fizz and the carbonate would disappear

Question 56

What is the test for carbon dioxide gas?

Answer 56

Bubble through lime water and the lime water goes cloudy

Question 57

What is a precipitate?

Answer 57

A solid formed in a solution reaction

Question 58

Name two groups of compounds that are always soluble

Answer 58

All group 1 metal compounds, all nitrates

Question 59

Name two insoluble chlorides

Answer 59

Silver chloride, lead chloride

Question 60

Name two insoluble sulphates

Answer 60

Barium sulphate, lead sulphate, calcium sulphate

Question 61

Which two groups of compounds are mostly insoluble?

Answer 61

Hydroxides and carbonates

Question 62

What is the rule for writing an equation for a precipitation reaction?

Answer 62

The ions from the two solutions reacting swap places

Question 63

What is the state symbol for a precipitate?

Answer 63

(s) solid

Question 64

In a solution precipitation reaction which state symbols would you expect to see in reactants and products?

Answer 64

reactants both would be (aq). Products one would be (aq) and one (s)

Question 65

List the steps to make an insoluble salt from a precipitation reaction

Answer 65

Add the two solutions together in the right quantities, filter off the precipitate, wash with some water, dry in an oven