# Topic 6 Quantitative analysis, equilibrium, fuel cells Flashcards

1
Q
1. What is the relative formula mass of magnesium oxide, MgO?
A

40

2
Q
1. What is the relative formula mass of water, H2O?
A

18

3
Q
1. What is the relative formula mass of carbon dioxide, CO2?
A

44

4
Q
1. What is the relative formula mass of sulfuric acid, H2SO4?
A

98

5
Q
1. What is the empirical formula of a compound with molecular formula C2H6?
A

CH3

6
Q
1. What is the empirical formula of a compound with molecular formula C6H6?
A

CH

7
Q
1. H What is the mass of 1 mole of sodium chloride, NaCl?
A

58.5 g

8
Q
1. H What is the mass of 0.1 mole of sulfur dioxide, SO2?
A

6.4 g

9
Q
1. What mass of water should be formed when 2 g of hydrogen reacts with 16 g of oxygen?
A

18 g

10
Q
1. What mass of magnesium oxide should be formed when 2.4 g of magnesium reacts with 1.6 g of oxygen?
A

4.0 g

11
Q
1. What is meant by the actual yield?
A

the actual amount of product formed in a reaction

12
Q
1. What is meant by the theoretical yield?
A

the maximum mass of product calculated from the balanced equation

13
Q
1. What is the formula for calculating percentage yield?
A

(actual yield/theoretical yield) × 100%

14
Q
1. What is the percentage yield if the actual yield is 60 g and the theoretical yield is 100 g?
A

60%

15
Q
1. What is the percentage yield if the actual yield is 5.5 g and the theoretical yield is 10 g?
A

55%

16
Q
1. What is the percentage yield if the actual yield is 15 g and the theoretical yield is 20 g?
A

75%

17
Q
1. What is the percentage yield if the actual yield is 0.1 g and the theoretical yield is 0.5 g?
A

20%

18
Q
1. Give one reason why the actual yield is less than the theoretical yield.
A

incomplete reaction, practical losses or competing reactions

19
Q
1. What is the relative formula mass of calcium hydroxide, Ca(OH)2?
A

74

20
Q
1. What is the relative formula mass of magnesium nitrate, Mg(NO3)2?
A

148

21
Q
1. What is meant by a solute?
A

a substance that dissolves in a liquid

22
Q
1. What is meant by a solvent?
A

the liquid that dissolves the solute

23
Q
1. How many cm3 are there in 1 dm3?
A

1000

24
Q
1. What is the concentration, in g dm-3, of 100 cm3 of a solution containing 2 g of solute?
A

20 g dm-3

25
Q
1. What is the concentration, in g dm-3, of 500 cm3 of a solution containing 5 g of solute?
A

5 g dm-3

26
Q
1. What is the concentration, in g dm?3, of 250 cm3 of a solution containing 4 g of solute?
A

4 g dm-3

27
Q
1. What is the amount, in moles, of hydrochloric acid, HCl, in 36.5 g?
A

1 mol

28
Q
1. What is the amount, in moles, of sodium hydroxide, NaOH, in 20 g?
A

0.5 mol

29
Q
1. What is the concentration of hydrochloric acid, in mol dm-3, if the concentration is 36.5 g dm-3?
A

1 (mol dm-3)

30
Q
1. What is the concentration of sodium hydroxide in mol dm-3, if the concentration is 20 g dm-3?
A

(0.5 (mol dm-3))

31
Q
1. What are the two substances formed when an acid reacts with an alkali?
A

salt and water

32
Q
1. What type of reaction takes place when an acid reacts with an alkali?
A

neutralisation

33
Q
1. Is potassium hydroxide an acid, an alkali or a salt?
A

alkali

34
Q
1. Is sodium sulfate an acid, an alkali or a salt?
A

salt

35
Q
1. What is used to show that a solution is acidic, alkaline or neutral?
A

an indicator

36
Q
1. What colour is phenolphthalein in an acidic solution?
A

colourless

37
Q
1. What colour is methyl orange in an alkaline solution?
A

yellow

38
Q
1. What measuring instruments are used to measure the accurate volumes of acid and alkali in a titration?
A

burette and pipette

39
Q
1. H How many moles of solute are there in 2 dm3 of 0.1 mol dm-3 hydrochloric acid?
A

0.2 mol

40
Q
1. H How many moles of solute are there in 100 cm3 of 0.1 mol dm-3 hydrochloric acid?
A

0.01 mol

41
Q
1. What is the abbreviation used for the mole, the unit for amount of substance?
A

mol

42
Q
1. How many particles are there in 1 mole of particles?
A

6.02 × 1023

43
Q
1. The mass of 1 mole of carbon atoms is 12 g. What is the mass of 2 moles of carbon atoms?
A

24 g

44
Q
1. 2 g of hydrogen gas contains 1 mole of hydrogen molecules. How many moles are there in 1 g of hydrogen molecules?
A

0.5 mol

45
Q
1. Each water molecule contains three atoms. How many moles of atoms are there in 2 moles of water molecules?
A

6 mol

46
Q
1. The relative formula mass of chlorine gas is 71. What is the mass of 1 mole of chlorine gas?
A

71 g

47
Q
1. What happens to the volume of a gas if its pressure is increased but its temperature is kept the same?
A

volume decreases

48
Q
1. What happens to the volume of a gas if its temperature is increased but its pressure is kept the same?
A

volume increases

49
Q
1. What is 100 dm3 in cm3?
A

100 000 cm3

50
Q
1. 0.5 mol of salt is dissolved in 2 dm3 of water. What is the concentration of the solution?
A

0.25 mol dm–3

51
Q
1. What are the chemical symbols for the elements nitrogen, potassium and phosphorus?
A

N, P, K

52
Q
1. What two gases react together to produce ammonia in the Haber process?
A

nitrogen, hydrogen

53
Q
1. What temperature is used in the Haber process?
A

450 °C

54
Q
1. What pressure is used in the Haber process?
A

200 atmospheres

55
Q
1. Why is iron used in the Haber process?
A

It is the catalyst/it makes the reaction go faster.

56
Q
1. Is ammonium sulfate soluble or insoluble in water?
A

soluble

57
Q
1. Name the acid needed to produce ammonium nitrate.
A

nitric acid

58
Q
1. Name the acid needed to produce ammonium sulfate.
A

sulfuric acid

59
Q
1. What method produces a solution containing only salt and water from an acid and alkali?
A

titration/neutralisation

60
Q
1. There is only one product in the Haber process. What is the atom economy of the process?
A

100%

61
Q
1. Write down or describe the symbol used for reversible reactions.
A

62
Q
1. Do the reactions keep going when a reversible reaction reaches equilibrium?
A

yes

63
Q
1. Do the concentrations of the reacting substances change at equilibrium?
A

no

64
Q
1. What compound is manufactured in the Haber process?
A

ammonia

65
Q
1. If the temperature is increased in a dynamic equilibrium, does the position move towards the endothermic reaction or towards the exothermic reaction?
A

towards the endothermic reaction

66
Q
1. If the pressure is increased in a dynamic equilibrium involving gases, does the position move towards the fewest number of moles of gas?
A

yes

67
Q
1. Compared with the theoretical yield, is the actual yield of product usually less, the same or more?
A

less

68
Q
1. What happens to the rate of a reaction if the temperature is increased?
A

it increases

69
Q
1. What happens to the rate of a reaction if a suitable catalyst is added?
A

it increases

70
Q
1. Does a catalyst get used up in the reaction it catalyses?
A

no

71
Q
1. Which is more reactive, zinc or iron?
A

zinc

72
Q
1. Name the ion released by acids when they dissolve in water.
A

hydrogen/H+

73
Q
1. Name the product formed when hydrogen reacts with oxygen.
A

water

74
Q
1. What charged particles move through the liquid during electrolysis?
A

ions

75
Q
1. In what type of reaction is energy transferred to the surroundings?
A

exothermic

76
Q
1. What is the unit for electrical potential difference?
A

volt/V

77
Q
1. In electrolysis, what do we call the ionic compounds that are decomposed?
A

electrolytes

78
Q
1. What is the approximate voltage of a typical AA battery?
A

1.5 V

79
Q
1. What fuel is used in a hydrogen–oxygen fuel cell?
A

hydrogen

80
Q
1. What is oxidation?
A

reaction with oxygen/gain of oxygen/loss of electrons