Topic 5a Mass calculations, electrolysis, extraction of metals and equilibria Flashcards Preview

Edexcel GCSE Combined Science (Chemistry) 2022 > Topic 5a Mass calculations, electrolysis, extraction of metals and equilibria > Flashcards

Flashcards in Topic 5a Mass calculations, electrolysis, extraction of metals and equilibria Deck (110)
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1
Q
  1. What is the formula of water?
A

H2O

2
Q
  1. What is the formula of sodium chloride?
A

NaCl

3
Q
  1. What is the formula of carbon dioxide?
A

CO2

4
Q
  1. The formula of magnesium chloride is MgCl2. What is the ratio of magnesium ions to chloride ions?
A

1:2

5
Q
  1. The formula of sulfuric acid is H2SO4. How many atoms of each element are in the formula?
A

H = 2, S = 1, O = 4

6
Q
  1. The formula of calcium nitrate is Ca(NO3)2. How many calcium, nitrogen and oxygen atoms are in the formula?
A

Ca = 1, N = 2, O = 6

7
Q
  1. There are two numbers alongside chlorine in the periodic table, 17 and 35.5. What does the number 17 represent?
A

atomic number

8
Q
  1. What does the number 35.5 represent?
A

relative atomic mass

9
Q
  1. Sodium chloride has the formula NaCl. The relative atomic mass of sodium is 23 and that of chlorine is 35.5. What is the relative formula mass of NaCl?
A

58.5

10
Q
  1. A water molecule has the formula H2O. The relative atomic mass of hydrogen is 1 and that of oxygen is 16. What is the relative formula mass of a molecule of water?
A

18

11
Q
  1. What is the symbol for relative atomic mass?
A

Ar or RAM

12
Q
  1. What is the symbol for relative formula mass?
A

Mr or RFM

13
Q
  1. The relative atomic mass of hydrogen is 1. What is the relative formula mass of hydrogen molecules?
A

2

14
Q
  1. Sodium chloride has the formula NaCl; the relative atomic mass of sodium is 23 and that of chlorine is 35.5. What is the relative formula mass of NaCl?
A

58.5

15
Q
  1. A water molecule has the formula H2O; the relative atomic mass of hydrogen is 1 and that of oxygen is 16. What is the relative formula mass of water?
A

18

16
Q
  1. A carbon dioxide molecule has the formula CO2; the relative atomic mass of carbon is 12 and that of oxygen is 16. What is the relative formula mass of carbon dioxide?
A

44

17
Q
  1. What is the empirical formula of a compound with molecular formula C2H4?
A

CH2

18
Q
  1. What is the empirical formula of a compound with molecular formula C3H8?
A

C3H8

19
Q
  1. A sample of magnesium carbonate was heated in an open test tube. Why did it lose mass?
A

gas/carbon dioxide escaped

20
Q
  1. 100 cm3 of a solution contained 2 g of salt. What is the concentration of the salt in g dm-3?
A

20

21
Q
  1. A sample of copper carbonate was heated in an open test tube. Why did it lose mass?
A

gas/carbon dioxide escaped

22
Q
  1. Why does magnesium increase in mass when it is heated in air?
A

combines with oxygen

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

1000

24
Q
  1. What is 250 cm3 expressed in dm3?
A

0.25

25
Q
  1. What is 0.5 dm3 expressed in cm3?
A

500

26
Q
  1. 100 cm3 of a solution contains 1.5 g of salt. What is the concentration of the salt solution in g dm3?
A

15

27
Q
  1. 250 cm3 of a solution contains 5 g of sugar. What is the concentration of the sugar solution in g dm3?
A

20

28
Q
  1. A solution of copper sulfate has concentration 10 g dm3. What mass of copper sulfate will be dissolved in 100 cm3 of solution?
A

1 g

29
Q
  1. 2 g of hydrogen reacts with oxygen to form 18 g of water. What mass of water will be formed from 1 g of hydrogen?
A

9 g

30
Q
  1. 2H2 + O2 → 2H2O. How many molecules of hydrogen are needed to react with 1 dozen molecules of oxygen to form water?
A

2 dozen

31
Q
  1. What is the abbreviation used for the mole, the unit for amount of substance?
A

mol

32
Q
  1. How many particles are there in 1 mole of particles?
A

6.02 x 1023

33
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

34
Q
  1. What is the formula for calculating the number of moles of substance from its mass in g
A

moles = mass (g) / RAM or RFM

35
Q
  1. Each water molecule contains three atoms. How many moles of atoms are there in 2 moles of water molecules?
A

6 mol

36
Q
  1. The relative formula mass of chlorine gas is 71. What is the mass of 1 mole of chlorine gas?
A

71 g

37
Q
  1. What is the Avogadro number?
A

6.02 x 1023 the number of atoms/particles in a mole

38
Q
  1. What is the emperical formula of a compound?
A

The simplist whole number ratio of atoms in compound

39
Q
  1. What is the law of conservation of mass?
A

total mass of reactants = total mass of products

40
Q
  1. How are the emperical formula and molecular formula related?
A

The molecular formula is a multiple of the emperical formula

41
Q
  1. What name is given to an atom that has gained or lost electrons?
A

ion

42
Q
  1. What type of charge is on metal and hydrogen ions?
A

positive

43
Q
  1. What type of charge is on most non-metal ions?
A

negative

44
Q
  1. What is another name for a positive ion?
A

cation

45
Q
  1. What is another name for a negative ion?
A

anion

46
Q
  1. What is the symbol for a sodium ion?
A

Na+

47
Q
  1. What is the symbol for a magnesium ion?
A

Mg2+

48
Q
  1. What is the symbol for a chloride ion?
A

Cl<span>-</span>

49
Q
  1. What is the symbol for a sulfate ion?
A

SO42-

50
Q
  1. In what states do ionic compounds conduct electricity?
A

when molten or dissolved in water

51
Q
  1. Which of these is not an electrolyte: solid sodium chloride, molten sodium chloride, aqueous sodium chloride?
A

solid sodium chloride

52
Q
  1. What is the name of the positively charged electrode?
A

anode

53
Q
  1. What type of ions are attracted to the positively charged electrode?
A

anions / negative ions

54
Q
  1. What is the name of the negatively charged electrode?
A

cathode

55
Q
  1. What type of ions are attracted to the negatively charged electrode?
A

cations / positive ions

56
Q
  1. H What process takes place when a substance gains electrons?
A

reduction

57
Q
  1. H In terms of subatomic particles, what happens to a substance when it is oxidised?
A

It loses electrons.

58
Q
  1. H What type of reaction takes place at the anode during electrolysis?
A

oxidation

59
Q
  1. What are inert electrodes made from?
A

graphite / platinum

60
Q
  1. What is produced at the cathode when molten lead bromide is electrolysed?
A

lead

61
Q
  1. What gas is formed when sodium reacts with water?
A

hydrogen

62
Q
  1. What solution is formed when sodium reacts with water?
A

sodium hydroxide

63
Q
  1. What colour is universal indicator when added to sodium hydroxide?
A

blue or purple

64
Q
  1. What gas is formed when magnesium is added to dilute sulfuric acid?
A

hydrogen (MASH)

65
Q
  1. What solution is formed when magnesium reacts with dilute sulfuric acid?
A

magnesium sulfate

66
Q
  1. What would you see when magnesium is added to dilute sulfuric acid?
A

effervescence/fizzing/bubbles/magnesium disappears

67
Q
  1. Name a metal that does not react with water or dilute acids.
A

copper/silver/gold/platinum

68
Q
  1. What products are formed when zinc is added to copper sulfate solution?
A

zinc sulfate and copper

69
Q
  1. What type of reaction takes place when zinc is added to copper sulfate solution?
A

displacement

70
Q
  1. Magnesium reacts with chromium nitrate solution to form magnesium nitrate and chromium. Which metal is more reactive?
A

magnesium

71
Q
  1. Name a metal that reacts vigorously with cold water.
A

potassium/sodium/rubidium/caesium/lithium/calcium

72
Q
  1. What gas is produced when a metal reacts with water?
A

hydrogen

73
Q
  1. How do you test for the gas produced in question 2?
A

It pops a lighted splint.

74
Q
  1. What type of solution is formed when a metal reacts with water - acidic, alkaline or neutral?
A

alkaline

75
Q
  1. What salt is formed when zinc reacts with hydrochloric acid?
A

zinc chloride

76
Q
  1. Complete the word equation, magnesium + copper sulfate makes …
A

copper + magnesium sulfate

77
Q
  1. What type of ions are formed from metal atoms when they react with acids?
A

cations/positive ions

78
Q
  1. What type of reaction takes place when a substance loses oxygen?
A

reduction

79
Q
  1. Name a metal that occurs uncombined in the Earths crust.
A

gold/silver/platinum

80
Q
  1. Name a metal that could be extracted from its metal oxide by heating with carbon.
A

zinc/iron/copper

81
Q
  1. Name a metal that occurs uncombined in the Earths crust.
A

gold/silver/platinum

82
Q
  1. Name a metal, other than iron, that could be extracted from its metal oxide by heating with carbon.
A

zinc/copper

83
Q
  1. What compound of carbon is formed when it is heated with copper oxide?
A

carbon dioxide/carbon monoxide

84
Q
  1. Why is electrolysis not used to extract iron from iron oxide?
A

too expensive/too much energy needed

85
Q
  1. Why is aluminium not extracted by heating aluminium oxide with carbon?
A

aluminium is more reactive than carbon/carbon is not reactive enough to remove the oxygen

86
Q
  1. What is the aluminium oxide dissolved in to form the electrolyte for electrolysis?
A

molten cryolite

87
Q
  1. What are the electrodes made from?
A

carbon/graphite

88
Q
  1. At which electrode is the aluminium produced?
A

cathode/negative electrode

89
Q
  1. What type of reaction takes place when a metal is extracted from its ore?
A

reduction/redox

90
Q
  1. What type of reaction takes place when a metal corrodes?
A

oxidation/redox

91
Q
  1. What is the definition of oxidation, in terms of oxygen?
A

gain of oxygen

92
Q
  1. H What is the definition of oxidation, in terms of electrons?
A

loss of electrons

93
Q
  1. What type of reaction takes place when metals are extracted from their ores?
A

reduction/redox

94
Q
  1. What is the specific name for the corrosion of iron?
A

rusting

95
Q
  1. Which of these metals will corrode most quickly - iron, sodium, copper?
A

sodium

96
Q
  1. Why does sodium corrode most quickly.
A

most reactive metal corrodes most quickly

97
Q
  1. Which substance has been oxidised in this reaction - copper oxide + hydrogen → copper + water?
A

hydrogen

98
Q
  1. Which substance has been reduced in in this reaction - copper oxide + hydrogen → copper + water?
A

copper oxide

99
Q
  1. What name is given to a process that converts an unwanted product into a new, useful product?
A

recycling

100
Q
  1. Name a type of substance that can be recycled.
A

metal, plastic, paper, cardboard, glass, etc.

101
Q
  1. What can happen in a reversible reaction?
A

the products can reform the reactants

102
Q
  1. What does the term equilibrium describe?
A

a position of balance

103
Q
  1. What is the process used to make ammonia?
A

Haber Process

104
Q
  1. What is the molecular formula of ammonia?
A

NH3

105
Q
  1. What is the balanced symbol equation for making ammonia from Nitrogen (N2) and Hydrogen (H2)
A

N2 +3H2 → 2NH3

106
Q
  1. Where does nitrogen come from for use in the Haber Process?
A

From the fractional distillation of air

107
Q
  1. Where does Hydrogen come from for use in the Haber process?
A

From methane from crude oil

108
Q
  1. What conditions of pressure are required to increase the yield of ammonia in the Haber Process?
A

High pressure (because there are more molecules on the LHS of the equation)

109
Q
  1. The forward reaction is exothermic. What conditions of temperature are required to increase the yield of ammonia in the Haber Process?
A

Low temperature (The equilibrium will shit to try and produce heat)

110
Q
  1. Theoretically, a high yield of ammonia is produce at low temperature and high pressure. Why is this not used in reality?
A

Low temperatue will result in a slow rate of reaction. High pressures are expensive and dangerous.