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

Edexcel GCSE Combined Science (Chemistry) > 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

1. What is the formula of water?

H2O

2

2. What is the formula of sodium chloride?

NaCl

3

3. What is the formula of carbon dioxide?

CO2

4

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

1:2

5

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

H = 2, S = 1, O = 4

6

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

Ca = 1, N = 2, O = 6

7

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

atomic number

8

8. What does the number 35.5 represent?

relative atomic mass

9

9. 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?

58.5

10

10. 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?

18

11

11. What is the symbol for relative atomic mass?

Ar or RAM

12

12. What is the symbol for relative formula mass?

Mr or RFM

13

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

2

14

14. 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?

58.5

15

15. 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?

18

16

16. 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?

44

17

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

CH2

18

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

C3H8

19

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

gas/carbon dioxide escaped

20

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

20

21

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

gas/carbon dioxide escaped

22

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

combines with oxygen

23

23. How many cm3 are there in 1 dm3?

1000

24

24. What is 250 cm3 expressed in dm3?

0.25

25

25. What is 0.5 dm3 expressed in cm3?

500

26

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

15

27

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

20

28

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

1 g

29

29. 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?

9 g

30

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

2 dozen

31

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

mol

32

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

6.02 x 1023

33

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

24 g

34

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

moles = mass (g) / RAM or RFM

35

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

6 mol

36

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

71 g

37

37. What is the Avogadro number?

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

38

38. What is the emperical formula of a compound?

The simplist whole number ratio of atoms in compound

39

39. What is the law of conservation of mass?

total mass of reactants = total mass of products

40

40. How are the emperical formula and molecular formula related?

The molecular formula is a multiple of the emperical formula

41

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

ion

42

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

positive

43

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

negative

44

44. What is another name for a positive ion?

cation

45

45. What is another name for a negative ion?

anion

46

46. What is the symbol for a sodium ion?

Na+

47

47. What is the symbol for a magnesium ion?

Mg2+

48

48. What is the symbol for a chloride ion?

Cl-

49

49. What is the symbol for a sulfate ion?

SO42-

50

50. In what states do ionic compounds conduct electricity?

when molten or dissolved in water

51

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

solid sodium chloride

52

52. What is the name of the positively charged electrode?

anode

53

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

anions / negative ions

54

54. What is the name of the negatively charged electrode?

cathode

55

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

cations / positive ions

56

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

reduction

57

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

It loses electrons.

58

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

oxidation

59

59. What are inert electrodes made from?

graphite / platinum

60

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

lead

61

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

hydrogen

62

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

sodium hydroxide

63

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

blue or purple

64

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

hydrogen (MASH)

65

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

magnesium sulfate

66

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

effervescence/fizzing/bubbles/magnesium disappears

67

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

copper/silver/gold/platinum

68

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

zinc sulfate and copper

69

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

displacement

70

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

magnesium

71

71. Name a metal that reacts vigorously with cold water.

potassium/sodium/rubidium/caesium/lithium/calcium

72

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

hydrogen

73

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

It pops a lighted splint.

74

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

alkaline

75

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

zinc chloride

76

76. Complete the word equation, magnesium + copper sulfate makes ...

copper + magnesium sulfate

77

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

cations/positive ions

78

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

reduction

79

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

gold/silver/platinum

80

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

zinc/iron/copper

81

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

gold/silver/platinum

82

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

zinc/copper

83

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

carbon dioxide/carbon monoxide

84

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

too expensive/too much energy needed

85

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

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

86

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

molten cryolite

87

87. What are the electrodes made from?

carbon/graphite

88

88. At which electrode is the aluminium produced?

cathode/negative electrode

89

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

reduction/redox

90

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

oxidation/redox

91

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

gain of oxygen

92

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

loss of electrons

93

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

reduction/redox

94

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

rusting

95

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

sodium

96

96. Why does sodium corrode most quickly.

most reactive metal corrodes most quickly

97

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

hydrogen

98

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

copper oxide

99

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

recycling

100

100. Name a type of substance that can be recycled.

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

101

101. What can happen in a reversible reaction?

the products can reform the reactants

102

102. What does the term equilibrium describe?

a position of balance

103

103. What is the process used to make ammonia?

Haber Process

104

104. What is the molecular formula of ammonia?

NH3

105

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

N2 +3H2  → 2NH3

106

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

From the fractional distillation of air

107

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

From methane from crude oil

108

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

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

109

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

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

110

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

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