Topic 7 Groups rates and energy

Question 1

1 What do atoms of the same element have in common?

Answer 1

their atomic number/number of protons

Question 2

2 Roughly how many elements are found naturally?

Answer 2

90 to 100

Question 3

3 In what order are elements arranged in the periodic table?

Answer 3

in order of increasing atomic number

Question 4

4 What do you call the columns in the periodic table?

Answer 4

groups

Question 5

5 What is special about the elements that are in the same group of the periodic table?

Answer 5

similar properties

Question 6

6 What is similar about the electronic configuration of elements in the same group?

Answer 6

same number of outer electrons

Question 7

7 What is formed when a group 1 element reacts with water?

Answer 7

an alkali/metal hydroxide + hydrogen

Question 8

8 What is the charge on the ions of elements in group 1?

Answer 8

1+

Question 9

9 The first two elements in group 1 are lithium and sodium. What is the third element?

Answer 9

potassium

Question 10

10 What name is given to group 1 elements?

Answer 10

the alkali metals

Question 11

11 What happens to the reactivity of the group 1 elements as you go down the group?

Answer 11

it increases

Question 12

12 What is produced when lithium reacts with water?

Answer 12

lithium hydroxide and hydrogen

Question 13

13 Why do alkali metals get more reactive as you go down the group?

Answer 13

the outermost electron is further and further away, and so more easily removed

Question 14

14 What name is given to group 7 elements?

Answer 14

the halogens

Question 15

15 State an example of a group 7 element.

Answer 15

one of: fluorine, chlorine, bromine, iodine or astatine

Question 16

16 What is the state of a substance at room temperature, if it has a melting point of ?7 °C and a boiling point of 59 °C?

Answer 16

liquid

Question 17

17 What ion is in all acid solutions?

Answer 17

H+

Question 18

18 Do metals usually form ionic compounds with other metals, non-metals, neither or both?

Answer 18

non-metals

Question 19

19 State the formula of the compound formed when calcium reacts with bromine.

Answer 19

CaBr₂

Question 20

20 What is the name and colour of the only liquid halogen?

Answer 20

bromine, brown

Question 21

21 What does chlorine look like?

Answer 21

pale green gas

Question 22

22 How is the appearance of iodine different from that of the three halogens above it in group 7?

Answer 22

solid and darker/black in colour

Question 23

23 Name the compound formed when hydrogen reacts with chlorine.

Answer 23

hydrogen chloride

Question 24

24 What kind of solution is formed when hydrogen fluoride dissolves in water – acidic, neutral or alkaline?

Answer 24

acidic

Question 25

25 Complete the equation: Ca(s) + Cl₂(g) →

Answer 25

CaCl₂(s)

Question 26

26 What ions are present in potassium fluoride?

Answer 26

K+ and FI^-

Question 27

27 State one similarity in the electronic configurations of fluorine and chlorine.

Answer 27

same number of outer electrons

Question 28

28 Describe the trend in reactivity of group 7 elements.

Answer 28

decreasing down the group

Question 29

29 What type of reaction occurs between chlorine and potassium bromide?

Answer 29

displacement and redox

Question 30

30 What is formed when chlorine water is added to sodium bromide solution?

Answer 30

sodium chloride + bromine

Question 31

31 What type of reaction is the reaction between chlorine water and sodium bromide solution an example of?

Answer 31

displacement, redox

Question 32

32 Fluorine atoms are more reactive than chlorine atoms. What does fluorine have fewer of that explains this?

Answer 32

electron shells

Question 33

33 **H** Describe reduction in terms of electron transfer.

Answer 33

gain of electrons

Question 34

34 Where is group 0 found in the periodic table?

Answer 34

last column on right-hand side

Question 35

35 What name is given to group 0 elements?

Answer 35

the noble gases

Question 36

36 Name a group 0 element.

Answer 36

one of: helium, neon, argon, krypton, xenon or radon

Question 37

37 What is similar about the electronic configuration of all group 0 elements?

Answer 37

full outer shell

Question 38

38 How are noble gases similar in terms of chemical properties?

Answer 38

all unreactive

Question 39

39 Describe the trend in the boiling points of the elements, down group 0.

Answer 39

increasing

Question 40

40 What happens to the reactants during a chemical reaction?

Answer 40

They are changed into new substances/products/used up.

Question 41

41 What happens to the rate of most reactions as the reaction proceeds?

Answer 41

It slows down.

Question 42

42 In reactions involving solutions, what happens to the rate if the concentrations at the start are decreased?

Answer 42

They become slower.

Question 43

43 What size of solid lumps reacts fastest in chemical reactions: small, medium or large?

Answer 43

small

Question 44

44 Apart from concentration and surface area, name one other variable that can change the speed of a chemical reaction.

Answer 44

temperature or pressure or catalyst

Question 45

45 What happens in a precipitation reaction?

Answer 45

A solid forms.

Question 46

46 What does it mean if effervescence is seen during a reaction?

Answer 46

A gas is being produced.

Question 47

47 What happens to the concentration of reactants as a reaction proceeds?

Answer 47

It decreases.

Question 48

48 What happens to the concentration of products as a reaction proceeds?

Answer 48

It increases.

Question 49

49 Why is there a loss in mass during the reaction between calcium carbonate and hydrochloric acid?

Answer 49

A gas is given off/lost.

Question 50

50 What usually happens to the rate of a reaction as the reaction proceeds?

Answer 50

It slows down.

Question 51

51 What happens to the concentration of reactants as a reaction proceeds?

Answer 51

It decreases.

Question 52

52 In a graph of concentration of products against time, how do you know when the reaction is finished?

Answer 52

The graph levels off.

Question 53

53 A reaction is followed by measuring the volume of gas produced. What other measurement could be used?

Answer 53

measuring mass lost

Question 54

54 What usually happens to the speed of a reaction as the temperature is decreased?

Answer 54

It gets slower.

Question 55

55 How does increasing the concentration of a solution affect the rate of reaction?

Answer 55

It increases the rate.

Question 56

56 What is the link between the size of the solid lumps and the surface area of a fixed mass of solid?

Answer 56

The smaller the lumps, the larger the surface area.

Question 57

57 What type of solid lumps will react fastest?

Answer 57

the smallest lumps or powders

Question 58

58 In reactions involving gases, how does gas pressure affect the reaction rate?

Answer 58

Increased pressure increases the rate.

Question 59

59 What must the reacting molecules do for a reaction to occur?

Answer 59

They must collide with enough energy.

Question 60

60 What has to happen before a reaction takes place?

Answer 60

Reacting molecules must collide with enough energy.

Question 61

61 Describe two ways of measuring reaction rates in a reaction that produces a gas.

Answer 61

measuring volume of gas formed and mass lost by reactants

Question 62

62 Explain how increasing concentrations increases the rate of a reaction.

Answer 62

More collisions occur.

Question 63

63 What change in condition increases the speed of the reacting molecules?

Answer 63

increasing temperature

Question 64

64 How can you increase the surface area of a solid?

Answer 64

Divide the solid into smaller pieces.

Question 65

65 Explain how increasing the surface area of a solid increases the rate of reaction.

Answer 65

More collisions can occur.

Question 66

66 Which change in condition only affects reactions involving gases?

Answer 66

pressure

Question 67

67 What is the activation energy in a reaction?

Answer 67

minimum energy needed by reactants for them to react

Question 68

68 What does a catalyst do?

Answer 68

speeds up a chemical reaction

Question 69

69 What do you call a biological catalyst?

Answer 69

an enzyme

Question 70

70 What do we call any substance that dissolves in a solvent to form a solution?

Answer 70

solute

Question 71

71 What products form when an acid is neutralised by an alkali?

Answer 71

a salt and water

Question 72

72 What do we call an insoluble substance that can form when two solutions are mixed?

Answer 72

precipitate

Question 73

73 Which substance, polystyrene or copper, is the better heat insulator?

Answer 73

polystyrene

Question 74

74 Energy is transferred by heating in three ways: convection, radiation and what else?

Answer 74

conduction

Question 75

75 Zinc reacts with copper sulfate solution. What solid product forms?

Answer 75

copper

Question 76

76 What gas is needed for fuels to burn?

Answer 76

oxygen

Question 77

77 Fuels may ignite if a spark hits them. What else can make a fuel ignite?

Answer 77

a flame/heating strongly

Question 78

78 Is energy transferred to or from the electrolyte during electrolysis?

Answer 78

to

Question 79

79 Give two ways by which energy is transferred to the surroundings in an explosion.

Answer 79

two from: by heating, by sound, by light, by a force

Question 80

80 What type of reaction takes in energy from the surroundings?

Answer 80

endothermic

Question 81

81 What happens to the temperature of an acid when an alkali is added to it?

Answer 81

It goes up/increases.

Question 82

82 What simple piece of apparatus is used to measure temperature?

Answer 82

thermometer

Question 83

83 What unit is used for energy?

Answer 83

J/joule/kJ/kilojoule

Question 84

84 What type of bond (ionic, covalent or metallic) exists between non-metals

Answer 84

covalent

Question 85

85 In combustion reactions, is energy taken in from the surroundings or given out?

Answer 85

given out

Question 86

86 How is energy transferred between reactants and surroundings during dissolving?

Answer 86

by heating

Question 87

87 Which of these reactions, displacement or precipitation, always heats up the surroundings?

Answer 87

displacement

Question 88

88 The temperature goes down when ammonium nitrate dissolves in water. Is this an exothermic process or an endothermic process?

Answer 88

endothermic

Question 89

89 Energy is taken in so that bonds can be broken. Is this an exothermic or an endothermic process?

Answer 89

endothermic

Question 90

90. Burning methane - endothermic or exothermic?

Answer 90

exothermic