chem_practice sec 4
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1. Which diagram shows the electronic structure of ammonia, NH3?
2. The table gives the atomic structures of four particles.
ParticleW X Y Z
Protons
Neutrons
Electrons
17
20
17
17
18
18
20
20
18
20
21
20
Which particles are present together in the same ionic solid?
A. W and XB. W and YC. X and YD. X and Z
3. Which molecule contains double covalent bonds?
A. Carbon dioxide, CO2
B. Chlorine, Cl2
C. Hydrogen chloride, HClD. Methane, CH4
4. The diagram shows the electron arrangement in a molecule of the compound YZ2.
Which pair of elements could be Y and Z?
Y Z
A. Calcium FluorineB. Carbon OxygenC. Oxygen HydrogenD. Sulphur Chlorine
5. The ion of a newly discovered metal X has the symbol X3+. What will be the formula of its chloride?
A. XCl3
B. X2Cl3
C. X3ClD. X3Cl2
6. Which of the following does not react with dilute hydrochloric acid?
A. Magnesium hydroxideB. Magnesium metalC. Magnesium nitrateD. Magnesium oxide
7. The approximate pH values of aqueous solutions of four substances commonly used in cooking are shown. Which substance could be taken to neutralize excess acid in the stomach?
Substance pH
A
B
C
D
baking soda
salt
lemon juice
vinegar
9
7
4
3
8. Which property of ethanoic acid is not a typical property of an acid?
A. It burns in air.B. It reacts with copper(II) oxide.C. It reacts with sodium carbonate.D. It reacts with magnesium.
9. What is the ionic equation for the neutralization of aqueous sodium hydroxide with dilute nitric acid?
A. H+ + OH H2OB. HNO3 + OH H2O + NO3
C. Na+ + NO3 NaNO3
D. Na+ + HNO3 NaNO3 + H+
10. In an accident in a factory, some nitric acid was spilt. Which substance, when added in excess, would neutralize the acid without leaving an alkaline solution?
A. Aqueous ammoniaB. Aqueous sodium hydroxideC. Calcium carbonateD. Water
11. __________________ is not a salt.
A. Calcium sulphateB. Copper(II) chlorideC. Magnesium hydroxideD. Silver iodide
12. The pH values of five aqueous solutions P, Q, R, S and T are shown.
What could the aqueous solutions be?
Ammonia Ethanoicacid
Hydrochloric acid
Potassium chloride
Potassium hydroxide
A
B
C
D
Q
R
R
S
S
P
T
Q
T
Q
S
P
R
S
Q
R
P
T
P
T
13. The colour of Universal Indicator in each of four solutions is shown in the table.
Which solution is likely to be an acid of pH 2-3?
Colour of Universal Indicator paper
A Blue
B
C
D
Green
Red
Violet
14. Four aqueous solutions have the pH values shown in the table.
Solution
P Q R S
pH 2 6 8 10
If pairs of the solutions are mixed, which pair must produce an acidic mixture?
A. P and QB. P and RC. P and SD. Q and R
15. The table shows the results of adding dilute hydrochloric acid and aqueous sodium hydroxide to four oxides.
Which oxide is amphoteric?
Result of addingDilute hydrochloric
acidAqueous sodium
hydroxide
A
B
C
D
no reaction
no reaction
reaction
reaction
reaction
no reaction
reaction
no reaction
16. Which of the following is an amphoteric oxide?
A. Copper(II) oxideB. Magnesium oxideC. Sulphur dioxideD. Zinc oxide
17. Which substance reacts with water to give a solution of pH value greater than 7?
A. AmmoniaB. Carbon dioxideC. Nitrogen dioxide
D. Sodium chloride
18. Which salt can be prepared by an acid-alkali titration method?
A. Ammonium sulphateB. Copper(II) sulphateC. Iron(II) sulphateD. Zinc sulphate
19. In which reaction is a salt not formed?
A. Copper(II) sulphate with barium chlorideB. Copper(II) sulphate with sodium hydroxideC. Copper(II) oxide with hydrogenD. Copper(II) oxide with dilute sulphuric acid
20. In the following are listed five salts and the suggested methods for preparing them. Which one of the following is wrongly matched?
Salt Suggested method for preparation
A. KCl neutralisationB. PbSO4 precipitationC. FeS direct combinationD. Na2CO3 neutralisation
21. The alloy solder (Pb/Sn) is used for joining metals together because it ___________.
A. is stronger than pure metalsB. appears more attractive than pure metalsC. has a lower melting point than pure metalsD. has more resistance to corrosion than pure metals
22. Which one of the following pairs of elements is present in brass?
A. Aluminium and zincB. Copper and zincC. Copper and leadD. Copper and tin
23. Which process is used to extract aluminium metal from its ore?
A. By heating with copperB. Electrolysis of its molten oreC. Reduction using carbonD. Reduction using hydrogen
24. Which substance cannot reduce iron(III) oxide to iron?
A. Calcium carbonate
B. Carbon monoxideC. CokeD. Hydrogen
25. An element X reacts very slowly with cold water, but reacts vigorously with steam.Which statement about the reactivity of element X is correct?
A. It is less reactive than copper.B. It is less reactive than iron.C. It is more reactive than sodium.D. It is more reactive than silver.
26. Why is limestone added to the blast furnace in the manufacture of iron?
A. It raises the temperature of the blast furnace.B. It lowers the melting point of iron ore.C. It reduces the iron ore to iron.D. It removes impurities.
27. Iron occurs in nature as _____________.
A. iron(II) sulphateB. iron(II) chlorideC. iron(III) chlorideD. iron(III) oxide
28. Which of the following is the reducing agent used in the production of iron in a blast furnace?
A. AirB. Carbon dioxideC. Carbon monoxideD. Limestone
29. A student set up an experiment using iron nails, as shown. In which tube does most rusting take place after one week?
30. The table shows some metals and their uses.
For which metal is the correct reason given for the stated use?metal use reason
A
B
C
D
Aluminium
Copper
Iron
Zinc
Cooking pot
Electrical wiring
Manufacturing stainless steel
Galvanizing iron
High density
Good heat conductor
It rusts
Zinc is more reactive than iron
31. Which diagram shows the electronic structure of ammonia, NH3? C
32. The table gives the atomic structures of four particles.
ParticleW X Y Z
Protons
Neutrons
Electrons
17
20
17
17
18
18
20
20
18
20
21
20
Which particles are present together in the same ionic solid? C
E. W and XF. W and YG. X and YH. X and Z
33. Which molecule contains double covalent bonds? A
A. Carbon dioxide, CO2
B. Chlorine, Cl2
C. Hydrogen chloride, HClD. Methane, CH4
34. The diagram shows the electron arrangement in a molecule of the compound YZ2.
Which pair of elements could be Y and Z? D
Y Z
A. Calcium FluorineB. Carbon OxygenC. Oxygen HydrogenD. Sulphur Chlorine
35. The ion of a newly discovered metal X has the symbol X3+. What will be the formula of its chloride? A
A. XCl3
B. X2Cl3
C. X3ClD. X3Cl2
36. Which of the following does not react with dilute hydrochloric acid? C
A. Magnesium hydroxideB. Magnesium metalC. Magnesium nitrateD. Magnesium oxide
37. The approximate pH values of aqueous solutions of four substances commonly used in cooking are shown. Which substance could be taken to neutralize excess acid in the stomach? A
Substance pH
A
B
C
D
baking soda
salt
lemon juice
vinegar
9
7
4
3
38. Which property of ethanoic acid is not a typical property of an acid? A
A. It burns in air.B. It reacts with copper(II) oxide.C. It reacts with sodium carbonate.D. It reacts with magnesium.
39. What is the ionic equation for the neutralization of aqueous sodium hydroxide with dilute nitric acid? A
A. H+ + OH H2OB. HNO3 + OH H2O + NO3
C. Na+ + NO3 NaNO3
D. Na+ + HNO3 NaNO3 + H+
40. In an accident in a factory, some nitric acid was spilt. Which substance, when added in excess, would neutralize the acid without leaving an alkaline solution?
CA. Aqueous ammoniaB. Aqueous sodium hydroxideC. Calcium carbonateD. Water
41. __________________ is not a salt. C
A. Calcium sulphateB. Copper(II) chlorideC. Magnesium hydroxideD. Silver iodide
42. The pH values of five aqueous solutions P, Q, R, S and T are shown.
What could the aqueous solutions be? D
Ammonia Ethanoicacid
Hydrochloric acid
Potassium chloride
Potassium hydroxide
A
B
C
D
Q
R
R
S
S
P
T
Q
T
Q
S
P
R
S
Q
R
P
T
P
T
43. The colour of Universal Indicator in each of four solutions is shown in the table.
Which solution is likely to be an acid of pH 2-3? C
Colour of Universal Indicator paper
A Blue
B
C
D
Green
Red
Violet
44. Four aqueous solutions have the pH values shown in the table.
Solution
P Q R S
pH 2 6 8 10
If pairs of the solutions are mixed, which pair must produce an acidic mixture?A
E. P and QF. P and RG. P and SH. Q and R
45. The table shows the results of adding dilute hydrochloric acid and aqueous sodium hydroxide to four oxides.
Which oxide is amphoteric? C
Result of addingDilute hydrochloric
acidAqueous sodium
hydroxide
A
B
C
D
no reaction
no reaction
reaction
reaction
reaction
no reaction
reaction
no reaction
46. Which of the following is an amphoteric oxide? D
A. Copper(II) oxideB. Magnesium oxideC. Sulphur dioxideD. Zinc oxide
47. Which substance reacts with water to give a solution of pH value greater than 7?A
A. AmmoniaB. Carbon dioxideC. Nitrogen dioxide
D. Sodium chloride
48. Which salt can be prepared by an acid-alkali titration method? A
A. Ammonium sulphateB. Copper(II) sulphateC. Iron(II) sulphateD. Zinc sulphate
49. In which reaction is a salt not formed? C
A. Copper(II) sulphate with barium chlorideB. Copper(II) sulphate with sodium hydroxideC. Copper(II) oxide with hydrogenD. Copper(II) oxide with dilute sulphuric acid
50. In the following are listed five salts and the suggested methods for preparing them. Which one of the following is wrongly matched? D
Salt Suggested method for preparation
A. KCl neutralisationB. PbSO4 precipitationC. FeS direct combinationD. Na2CO3 neutralisation
51. The alloy solder (Pb/Sn) is used for joining metals together because it ___________.A
A. is stronger than pure metalsB. appears more attractive than pure metalsC. has a lower melting point than pure metalsD. has more resistance to corrosion than pure metals
52. Which one of the following pairs of elements is present in brass? B
A. Aluminium and zincB. Copper and zincC. Copper and leadD. Copper and tin
53. Which process is used to extract aluminium metal from its ore? B
A. By heating with copperB. Electrolysis of its molten oreC. Reduction using carbonD. Reduction using hydrogen
54. Which substance cannot reduce iron(III) oxide to iron? D
A. Calcium carbonateB. Carbon monoxideC. CokeD. Hydrogen
55. An element X reacts very slowly with cold water, but reacts vigorously with steam.Which statement about the reactivity of element X is correct? D
A. It is less reactive than copper.B. It is less reactive than iron.C. It is more reactive than sodium.D. It is more reactive than silver.
56. Why is limestone added to the blast furnace in the manufacture of iron? D
A. It raises the temperature of the blast furnace.B. It lowers the melting point of iron ore.C. It reduces the iron ore to iron.D. It removes impurities.
57. Iron occurs in nature as _____________. D
A. iron(II) sulphateB. iron(II) chlorideC. iron(III) chlorideD. iron(III) oxide
58. Which of the following is the reducing agent used in the production of iron in a blast furnace? C
A. AirB. Carbon dioxideC. Carbon monoxideD. Limestone
59. A student set up an experiment using iron nails, as shown. In which tube does most rusting take place after one week? A
60. The table shows some metals and their uses.
For which metal is the correct reason given for the stated use? Dmetal use reason
A
B
C
D
Aluminium
Copper
Iron
Zinc
Cooking pot
Electrical wring
Manufacturing stainless steel
Galvanizing iron
High density
Good heat conductor
It rusts
Zinc is more reactive than iron
Section A [40m]
Answer ALL the questions in the spaces provided.
1. A solid compound X was heated steadily for 20 minutes. Its temperature varied as shown in the graph below.
(a) At what temperature did compound X melt? __________________ [1]
(b) What is the highest temperature at which X can exist as a solid? [1]
__________________________________________________________________
(c) Would you expect X to be a solid, liquid or gas at the following temperatures?[1]
(i) 26°C _______________________
(ii) 50°C _______________________
(iii) 100°C _______________________
2. The atmosphere on a strange planet consists entirely of a green chemical element.Scientists studying the planet have given the element the chemical symbol Ze.The element does not conduct electricity. It combines with other elements to make covalent and ionic compounds. It forms the ion Ze.
(a) From the information above, give two reasons why the element should be classed as a non-metal. [2]
__________________________________________________________________
__________________________________________________________________
(b) Another element occurring on the planet is given the symbol Yn. It has a valency of 3 in its compound with Ze.
Write the formula of this compound of Yn and Ze. [1]
__________________________________________________________________
(c) Suggest why hydrogen will not burn on the planet to form water. [1]
__________________________________________________________________
3. (a) Explain briefly, in terms of the ions in solution, the reason for the differences in acidity and alkalinity of dilute hydrochloric acid, dilute sodium hydroxide and water. [2]
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
(b) A farmer decided to neutralize and fertilise his soil by adding at the same time both calcium oxide and an ammonium salt. Why was he wasting his time and money? [1]
__________________________________________________________________
__________________________________________________________________
4. The scale in kettles contains calcium carbonate. Aminosulphonic acid is used to remove this scale. This acid reacts with the scale and produces a gas.
The following apparatus was used to collect gas formed when an excess of the acid was added to a small amount of the scale.
(a) How could you tell that a gas is produced? [1]
__________________________________________________________________
(b) Name the gas produced. [1]
__________________________________________________________________
5. Dilute sulphuric acid reacts with a base such as sodium hydroxide.
(a) What word is used to describe this type of reaction? [1]
__________________________________________________________________
(b) What are formed when any acid reacts with any base? [2]
________________ and __________________
(c) What is the chemical formula of sulphuric acid? ________________ [1]
(d) State one use of sulphuric acid. [1]
__________________________________________________________________
6. (a) How can ammonia gas be made from ammonium sulphate? [1]
__________________________________________________________________
(b) When ammonia is dissolved in water, aqueous ammonia results.How could you show that aqueous ammonia is alkaline? [1]
__________________________________________________________________
(c) An excess of dilute hydrochloric acid is added to aqueous ammonia drop by drop.
(i) What happens to the pH of the mixture? [2]
__________________________________________________________________
(ii) State the formula of the salt formed. [1]
__________________________________________________________________
7. State the method of extraction suitable for the following metals : [3]
(a) Sodium _________________________
(b) Zinc _________________________
(c) Calcium _________________________
8. Complete the following table below. [3]
Name of alloy Main elements present in Important use of alloy
alloy
(a) stainless steel
(b) mild steelMotorcar bodies,
machinery
9. (a) Explain, with the aid of diagrams, why an alloy is stronger than a pure metal. [4]
Pure metal Alloy
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
(b) Iron is often alloyed to reduce rusting. Name an element used for this purpose. [1]
_____________________________________________________________________
10. Suggest why [2]
(a) mild steel should not be used for making knives and forks.
__________________________________________________________________
(b) aluminium is used in the manufacture of airplane wings.
__________________________________________________________________
11. Rust is also known as iron(III) oxide.
(a) State the conditions for rusting to take place. [2]
__________________________________________________________________
(b) (i) Give two methods of rust prevention. [2]
__________________________________________________________________
(ii) Explain how one of the methods you have given in (i) prevents rusting.[1]
__________________________________________________________________
__________________________________________________________________
SECTION B [ 30m]
Answer any THREE questions in the writing papers provided.
B1. Read the following passage and answer the questions below.
(a) An ore of iron, A, is mixed with coke and limestone and loaded into a blast furnace.Hot B is blasted in through a ring of pipes at the base of the furnace.
The coke burns producing gas C which is reduced by reaction with more coke to give gas D. This gas reduces the iron ore to iron.
The limestone decomposes to form carbon dioxide and a white solid E which reacts with silica, SiO2, to give a molten slag containing calcium silicate.
(i) Identify A, B, C, D and E. [5]
(ii) Compound E is basic. What does this tell you about a chemical property of silica? [1]
(iii) Write a balanced chemical equation for the reaction between iron ore and gas D. [1]
(b) Describe what you would see if pieces of zinc metal were placed in a solution of copper(II) sulphate.
Write a balanced chemical equation for the reaction, including the state symbols for the reactants and products. [3]
B2. Copper(II) sulphate crystals, CuSO4, are soluble in water.
(a) Describe how these crystals could be prepared from a named dilute acid and a suitable compound of copper. [8]
(b) Write a balanced chemical equation, including state symbols, for the reaction above.[2]
B3. (a) Explain, with a labeled diagram of the apparatus you would use, for obtaining pure water from seawater. [4]
(b) These two drawings show the results of putting strips of magnesium and chromium into tin chloride solutions.
(a) Use these results to decide whether tin is [2]
(i) more or less reactive than magnesium
(ii) more or less reactive than chromium
(b) Draw a labeled diagram of a similar experiment which will enable
you to decide the order of reactivity of chromium and magnesium. [2]
(c) State the method you would use to separate the following: [2]
(i) The dyes that are present in ink.
(ii) Sulphur from a mixture of powdered sulphur and iron filings.
B4. (a) Explain what is meant by ‘The relative atomic mass of holmium is 165’.[1]
(b) Explain how it is possible for the relative mass of chlorine to be 35.5 when each atomic nucleus contains only whole numbers of protons and neutrons. [2]
(c) Show, by means of a diagram, the arrangement of electrons in an atom of nitrogen-15. [Proton number = 7 and Mass number = 15]
Include in your diagram the composition of the nucleus of the atom. [2]
(d) The figure is a diagram showing the atomic structure of an isotope of common element X.
(i) State the proton number of X.(ii) State the nucleon number of this isotope of X.(iii) Is X a metal or non-metal. Give a reason for your answer.
(iv) In which group would you place element X? Give a reason for your answer.
(v) Write the formula of the ion of X that you would expect to exist in its ionic compound. [5]
Section A [40m]
Answer ALL the questions in the spaces provided.
1. A solid compound X was heated steadily for 20 minutes. Its temperature varied as shown in the graph below.
(a) At what temperature did compound X melt? 40 C [1]
(b) What is the highest temperature at which X can exist as a solid? [1]39 C - 39.9 C [accepted]
(c) Would you expect X to be a solid, liquid or gas at the following temperatures?[1]
(i) 26°C solid
(ii) 50°C liquid
(iii) 100°C gas
2. The atmosphere on a strange planet consists entirely of a green chemical element.Scientists studying the planet have given the element the chemical symbol Ze.The element does not conduct electricity. It combines with other elements to make covalent and ionic compounds. It forms the ion Ze.
(a) From the information above, give two reasons why the element should be classed as a non-metal. [2]
Does not conduct electricity, forms a negative ion, gas
(b) Another element occurring on the planet is given the symbol Yn. It has a valency of 3 in its compound with Ze.
Write the formula of this compound of Yn and Ze. YnZe3 [1]
(c) Suggest why hydrogen will not burn on the planet to form water. [1]No oxygen present in the planet’s atmosphere.
3. (a) Explain briefly, in terms of the ions in solution, the reason for the differences in acidity and alkalinity of dilute hydrochloric acid, dilute sodium hydroxide and water. [2]
Acid contains hydrogen ions only. Alkali contains hydroxide ions only. Water contains the same number of hydrogen and hydroxide ions.
(b) A farmer decided to neutralize and fertilise his soil by adding at the same time both calcium oxide and an ammonium salt. Why was he wasting his time and money? [1]
Calcium oxide, being a base will react with ammonium salt.
4. The scale in kettles contains calcium carbonate. Aminosulphonic acid is used to remove this scale. This acid reacts with the scale and produces a gas.
The following apparatus was used to collect gas formed when an excess of the acid was added to a small amount of the scale.
(a) How could you tell that a gas is produced? [1]Bubbles seen / movement of syringe
(b) Name the gas produced. [1]Carbon dioxide gas
5. Dilute sulphuric acid reacts with a base such as sodium hydroxide.
(a) What word is used to describe this type of reaction? [1]Neutralisation reaction
(b) What are formed when any acid reacts with any base? [2]
Salt and water
(c) What is the chemical formula of sulphuric acid? H2SO4 [1]
(d) State one use of sulphuric acid. [1]
Manufacture fertilizers / manufacture detergents / in car batteries
6. (a) How can ammonia gas be made from ammonium sulphate? [1]
By reacting with a base
(b) When ammonia is dissolved in water, aqueous ammonia results.How could you show that aqueous ammonia is alkaline? [1]Red litmus paper turns blue/ pH meter shows a value above 8/ Universal indicator turns purple.
(c) An excess of dilute hydrochloric acid is added to aqueous ammonia drop by drop.
(i) What happens to the pH of the mixture? [2]pH value decreases [1] to a pH value of less than 7 [1].
(ii) State the formula of the salt formed. NH4Cl [1]
7. State the method of extraction suitable for the following metals : [3]
(a) Sodium electrolysis
(b) Zinc reduction
(c) Calcium electrolysis
8. Complete the following table below. [3]
Name of alloyMain elements present in
alloyImportant use of alloy
(a) stainless steel Iron, chromium
Surgical instruments/ cutlery
(b) mild steel Iron, CarbonMotorcar bodies,
machinery
9. (a) Explain, with the aid of diagrams, why an alloy is stronger than a pure metal. [4]
Same sized atoms closely packed and in regular pattern [1]
2 different sized atoms, close together, not regularly ordered [1]
Pure metal Alloy
In a pure metal, the atoms are arranged in an orderly manner [1/2]. When force is applied, the layers of atoms are able to slide past each other [1/2]. In an alloy, the bigger atoms disrupt [1/2] the regular arrangement which prevents [1/2] the layers of atoms from sliding past each other.
(b) Iron is often alloyed to reduce rusting. Name an element used for this purpose. [1]
Chromium / Carbon / Nickel
10. Suggest why [2]
(a) mild steel should not be used for making knives and forks.Mild steel can rust
(b) aluminium is used in the manufacture of airplane wings.Low density
11. Rust is also known as iron(III) oxide.
(a) State the conditions for rusting to take place. [2]Air / Oxygen and water/water vapour
(b) (i) Give two methods of rust prevention. [2]Paint, grease, galvanise, sacrificial protection
(ii) Explain how one of the methods you have given in (i) prevents rusting.[1]
The coating prevents the iron from being in contact with oxygen and water.
SECTION B [ 30m]
Answer any THREE questions in the writing papers provided.
B1. Read the following passage and answer the questions below.
(a) An ore of iron, A, is mixed with coke and limestone and loaded into a blast furnace.Hot B is blasted in through a ring of pipes at the base of the furnace.
The coke burns producing gas C which is reduced by reaction with more coke to give gas D. This gas reduces the iron ore to iron.
The limestone decomposes to form carbon dioxide and a white solid E which reacts with silica, SiO2, to give a molten slag containing calcium silicate.
(i) Identify A, B, C, D and E. [5]
A – haematite / iron(III) oxide sp -1/2m B – air
C – carbon dioxideD – carbon monoxideE – calcium oxide
[Formulae may be accepted]
(ii) Compound E is basic. What does this tell you about a chemical property of silica? [1]Silica is acidic.
(iii) Write a balanced chemical equation for the reaction between iron ore and gas D. [1]
Fe2O3 + 3CO 2Fe + 3CO 2 not bal – 0m
(b) Describe what you would see if pieces of zinc metal were placed in a solution of copper(II) sulphate.
Write a balanced chemical equation for the reaction, including the state symbols for the reactants and products. [3]
Blue colour solution turns colourless [1/2]. Pink solid is deposited [1/2].
Zn (s) + CuSO4 (aq) Cu (s) + ZnSO 4 (aq) bal eqn [1], ss [1]
B2. Copper(II) sulphate crystals, CuSO4, are soluble in water.
(a) Describe how these crystals could be prepared from a named dilute acid and a suitable compound of copper. [8]
Heat dilute sulphuric acid in a beaker Add copper(II) oxide/copper(II) carbonate until excess and stir. Filter the mixture Evaporate most of the water in an evaporating dish Leave to cool
Each step – 1m, each reactant – 1m
(b) Write a balanced chemical equation, including state symbols, for the reaction above.[2]
CuO (s) + H2SO4 (aq) CuSO 4 (aq) + H2O (l) bal eqn [1], ss [1]
B3. (a) Explain, with a labeled diagram of the apparatus you would use, for obtaining pure water from seawater. [4]
Pure water can be obtained by seawater by simple distillation[1]. When the temperature reaches 100 C [1], pure water will be distilled out through the condenser.
Diagram of simple distillation [2]
(b) These two drawings show the results of putting strips of magnesium and chromium into tin chloride solutions.
(a) Use these results to decide whether tin is [2]
(i) more or less reactive than magnesium less reactive
(ii) more or less reactive than chromium less reactive
(b) Draw a labeled diagram of a similar experiment which will enable you to decide the order of reactivity of chromium and magnesium. [2]
similar diagram but using chromium and magnesium chloride / magnesium with chromium chloride.
(c) State the method you would use to separate the following: [2]
(i) The dyes that are present in ink. chromatography
(ii) Sulphur from a mixture of powdered sulphur and iron filings.Magnetic attraction
B4. (a) Explain what is meant by ‘The relative atomic mass of holmium is 165’.[1]The TOTAL NUMBER of protons and neutrons in an atom of holmium is 165
(b) Explain how it is possible for the relative mass of chlorine to be 35.5 when each atomic nucleus contains only whole numbers of protons and neutrons. [2]Chlorine has two isotopes with different abundance. [1]Cl 35 – 75% and Cl 37 – 25% [1]
(c) Show, by means of a diagram, the arrangement of electrons in an atom of nitrogen-15. [Proton number = 7 and Mass number = 15]
Include in your diagram the composition of the nucleus of the atom. [2]
Similar diagram as below showing 7protons and 8 neutrons [1]. Electronic structure showing 2,8,5 [1 paired and 3 single electrons] [1]
(d) The figure is a diagram showing the atomic structure of an isotope of common element X.
(i) State the proton number of X. 17
(ii) State the nucleon number of this isotope of X. 37
(iii) Is X a metal or non-metal. Give a reason for your answer. Non-metal. It has 7 valence electrons belonging to Group 7/ forms a negative ion since it has to gain one electron to form an octet.
[1] – if correct explanation
(iv) In which group would you place element X? Give a reason for your answer.Group 7. It has 7 valence electrons. [1] – if correct explanation
(v) Write the formula of the ion of X that you would expect to exist in its ionic compound. X [1] / Cl (1/2m) [5]
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