Download Chemistry Assignment 1 2013

Physical Science
Assignment - 2013
Criteria Assessed: 1
3
6
Chemistry
8
Name:________________
1. demonstrate personal skills to organise and complete activities
3. communicate ideas and information;
6. demonstrate knowledge and understanding of the principles of structures and properties of materials;
8. demonstrate knowledge and understanding of the principles of chemical reactions and change;
Questions 1 – 6 assess Criterion 6
Question 1
Complete the following table.
Symbol of
atom/ion
32
16
34
16
(5 marks)
Number of
protons
neutrons
electrons
6
8
6
20
21
13
15
Electron
configuration
S
S2–
2, 8, 8
10
Question 2
In terms of their electronic structure, explain why the noble gases (Group VIII) are extremely
unreactive.
(2 marks)
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Question 3
Identify the (i) period and (ii) group of the elements represented by the following atomic numbers:
(2 marks)
(a) 19
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(b) 34
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Question 4
The ion Na+ contains 10 electrons.
(1 mark)
(a) Write down the symbol and charge of an anion with the same number of electrons as Na+.
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(b) Explain why the metal sodium Na readily forms sodium ion Na+ when reacting with non metals.
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(c) Which is the more reactive metal, sodium or caesium? Explain why.
(2 marks)
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Question 5
(a) Draw a mass spectrum to illustrate element tungsten(W) containing four isotopes:
Tungsten-182 26.3% abundance
Tungsten-183 14.1% abundance
Tungsten-184 30.4% abundance
Tungsten-186 29.2% abundance
(3 marks)
(b) Calculate the relative atomic mass of tungsten.
(3 marks)
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Questions 6– 10 assess Criterion 8 (please show your working).
Question 6
Calculate each of the following:
(a)
The molar mass of copper(II)phosphate Cu3 (PO4 ) 2 .
(1 mark)
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(b) The number of moles of copper(II)phosphate in 2.46g of copper(II)phosphate. (1 mark)
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(c)
The percentage by mass of copper in copper(II)phosphate Cu3 (PO4 ) 2 .
(2 marks)
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Question 7
Aspirin, C9 H 8O4 is often taken to help relieve pain.
(a)
Determine the amount (mol) of 0.500g of aspirin?
(2 marks)
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(b)
Calculate the number of molecules of aspirin present in 0.500 g of aspirin.
(1 mark)
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(c)
Calculate the total number of atoms present in 0.500 g of aspirin.
(1 mark)
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(d)
Determine the number of oxygen atoms in 0.500 g of aspirin
(1 mark)
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Question 8
(a) Determine the mass of 9.50 1023 molecules of sulfur dioxide SO 2 .
(2 marks)
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(b) What is the mass of one molecule of sulfur dioxide SO 2 ?
(1 mark)
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Question 9
Oxalic acid is found in rhubarb leaves. It consists of 26.7% carbon, 71.1% oxygen and the remainder
hydrogen by mass.
(a)
Determine the empirical formula of oxalic acid.
(3 marks)
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(b)
It was found that 6.40 mol of oxalic acid had a mass of 576 g. Determine the molar mass of
oxalic acid.
(1 mark)
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(c)
Hence determine the molecular formula of oxalic acid.
(1 mark)
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