CHEMISTRYCHEMISTRY - A LEVEL - PREPARATION WORK

INTRODUCTIONA brief series of activities to develop the basic knowledge and skills that you willneed to start you A-level Chemistry course

Contents:

1. Atomic Structure p2

2. Bonding p9

3. Amount of Substance p13

4. Maths Skills p17

W W W. R O C H D A L E S F C . A C . U K | 0 1 7 0 6 7 6 9 8 0 0 | I N F O @ R O C H D A L E S F C . A C . U K

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1. Atomic Structure 1.1 – 1.2 Fundamental Particles (Notes booklet pages 2-5) Task 1

Table 1: Complete the table by working out the missing numbers

ATOM ATOMIC NUMBER

MASS NUMBER PROTONS NEUTRONS ELECTRONS

C 6 12

P 15 16

K 39 19

Fe 30 26

Br 35 45

Co 59 32

Table 2: Complete the table by working out the missing numbers

ION ATOMIC NUMBER

MASS NUMBER PROTONS NEUTRONS ELECTRONS

Na+ 23 11

O2− 16 8

Ti3+ 22 26

I− 53 74

Fe2+ 26 56

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Deduce the number of protons, neutrons and electrons in the following species:

1. 11H Protons:____ Neutrons:___ Electrons:___

2. 178O Protons:____ Neutrons:___ Electrons:___

3. 42He2+ Protons:____ Neutrons:___ Electrons:___

4. 13254Xe Protons:____ Neutrons:___ Electrons:___

5. 2713Al3+ Protons:____ Neutrons:___ Electrons:___

6. 23592U Protons:____ Neutrons:___ Electrons:___

7. 11H+ Protons:____ Neutrons:___ Electrons:___

8. 4521Sc3+ Protons:____ Neutrons:___ Electrons:___

9. 3717Cl- Protons:____ Neutrons:___ Electrons:___

10. 146C Protons:____ Neutrons:___ Electrons:___

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Use the periodic table to write symbols for the following species in the form:

X where A = mass number, Z = atomic number, and X is the element symbol.

11. 19 protons, 20 neutrons, 18 electrons ______

12. 8 protons, 8 neutrons, 10 electrons ______

13. 1 proton, 2 neutrons, 1 electron ______

14. 82 protons, 126 neutrons, 80 electrons ______

15. 53 protons, 74 neutrons, 54 electrons ______

16. The element with 23 more protons and 33 more neutrons than and 35Cl atom.

17. The element with 7 fewer protons and 10 fewer neutrons than and 37Cl atom.

18. The element which has double the number of protons, neutrons and electrons as 14N.

A

Z

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1.3 Calculating Ar (Notes booklet p6)

Task 2: Calculate the Ar of the following elements from the mass spectrometry data:

1.

2.

3.

4.

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5. The mass spectrum of Uranium has three peaks at m/z 234, 235 and 238. These each have relative abundances of 0.006%, 0.72% and 99.2% respectively. Calculate the Ar of Uranium to 1 decimal place.

6. The mass spectrum of Copper has two peaks at m/z 63 and 65. These each have relative abundances of 69% and 31% respectively. Calculate the Ar of Copper to 1 decimal place.

7. The mass spectrum of Magnesium has three peaks at m/z 24, 25 and 26. These each have relative abundances of 78.99%, 10.00 and 11.01% respectively. Calculate the Ar of Magnesium to 1 decimal place.

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1.4 Electron Configuration (Notes booklet p7) Also see notes booklet p3 for a reminder on ions

Write out the electron configurations for the following atoms and ions.

1. Sodium: ______________ 2. Lithium: ______________ 3. Fluorine: ______________ 4. Calcium: ______________ 5. Sulfur: ______________ 6. Be2+ ______________ 7. F- ______________ 8. O2- ______________ 9. K+ ______________ 10. Ca2+ ______________

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2. Bonding (Notes booklet pages 8-17)

Task 1 (for this activity pages 8 and 17 will be the most useful)

Using the bonding summary table, identify the structure and bonding present in the following compounds:

Element/Compound Structure Bonding

1 Calcium

2 Sodium Chloride NaCl

3 Silicon Oxide SiO2

4 Iodine I2

5 Diamond

6 Potassium Oxide K2O

7 Calcium Carbonate CaCO3

8 Methane CH4

9 Phosphorus Oxide P4O10

10 Strontium

11 Argon

12 Mercury

13 Iron (II) Chloride FeCl2

14 Sulphur Dioxide SO2

15 Sodium Hydroxide NaOH

16 Lithium Hydride LiH

17 Sulfur Hexachloride SCl6

18 Graphene

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Task 2 (Notes booklet pages 8 and 17)

For the following compounds identify the bond or attractive force that is overcome when they change state. Identify which particles this force acts between.

Element/Compound Bond/Attractive Force The type of particles the force acts between

1 Calcium

2 Sodium Chloride NaCl

3 Silicon Oxide SiO2

4 Iodine I2

5 Diamond

6 Potassium Oxide K2O

7 Calcium Carbonate CaCO3

8 Methane CH4

9 Phosphorus Oxide P4O10

10 Strontium

11 Argon

12 Mercury

13 Iron (II) Chloride FeCl2

14 Sulphur Dioxide SO2

15 Sodium Hydroxide NaOH

16 Lithium Hydride LiH

17 Sulfur Hexachloride SCl6

18 Graphene

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2.1 - Metallic Bonding (Notes p9-10)

Task 3: - In the two boxes below, draw diagrams to represent the metallic bonding present in (a) Lithium and (b) Aluminium. Each of your diagrams should contain at least 6 ions. State and explain which of the two metals will have the highest melting temperature.

Highest melting temperature:________________

Explanation:

(a) (b)

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2.2 - Ionic Bonding (Note booklet p11-12)

Task 4

Why do ionic compounds have a high melting point? [3]

Explain why there is a difference in electrical conductivity when an ionic compound is in a solid or a molten state. [2]

3) Copper is a metal with a high melting point.

(a) State the block in the Periodic Table that contains copper.

[1]

(b) Explain, in terms of its structure and bonding, why copper has a high melting point. [2]

(c) Draw a labelled diagram to show the arrangement of particles in a crystal of copper. In your answer, include at least six particles of each type.

[2]

(d) Explain why nickel is ductile (can be stretched into wires). [1]

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3. Amount of Substance (Notes booklet pages 18-23)

3.1 Balanced Equations

Task 1 (Note booklet pages 18-19)

Balance the following equations.

(a) PtCl4 à PtCl2 + Cl2

(b) H2 + Br2 à HBr

(c) PCl5 + H2O à POCl3 + HCl

(d) PCl3 + H2O à H3PO3 + HCl

(e) TiCl4 + H2O à TiO2 + HCl

(f) Al + H2SO4 à Al2(SO4)3 + H2

(g) Ca(NO3)2 à CaO + NO2 + O2

(h) C3H8 + O2 à CO2 + H2O

(i) Ca3(PO4)2 + C à Ca3P2 + CO

(j) Cu + HNO3 à Cu(NO3)2 + H2O + NO

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3.2 Relative atomic and molecular masses, the Avogadro constant,

and the mole (Note booklet pages 20-23)

Task 2

Relative atomic and molecular masses, the Avogadro constant, and mole

You will need a periodic table. Download from

https://filestore.aqa.org.uk/resources/chemistry/AQA-7405-SDB.PDF

The following information is also needed to answer these questions:

(1) Calculate the Ar for:

(a) Thallium (b) Selenium (c) Hafnium

(2) Calculate the Mr for:

(a) H2SO4 (b) NaBH4 (c) K2Cr2O7 (d) NH4Cl (e) C6H12O6

(f) Mg(OH)2 (g) Pt(NH3)2Cl2 (h) C3H8

(i) C3H6 (j) C3H7Cl

6.022x1023

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3.3 Number of Moles (Notes booklet pages 22-23)

(3) Calculate the number of moles present in the following:

(a) 14g of Kr (b) 103g of Ni (c) 42g of Os

(4) Calculate the number of moles present in the following:

(a) 27g of NaCl (b) 54g of Na2CO3 (c) 4g of SiO2

(5) Define the Avogadro Constant.

(6) Calculate the mass (in grams) of:

(a) 1 mole of Zn (b) 7.2 moles of F (c) 0.03 moles of U.

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(7) Calculate the mass (in grams) of:

(a) 3 moles of HCl (b) 0.32 moles of SO2 (c) 2.5 moles of chloroethane

(8) There is 3.94g of gold. Calculate:

(a) How many moles of gold this is. (b) How many gold atoms this is.

(9) There are 2.70g of aluminium. Calculate:

(a) How many moles of aluminium this is. (b)How many aluminium atoms this is.

(10) There are 3.54 x 1021 water molecules in a glass. Calculate:

(a) How many moles of H2O this is. (b) What the mass of H2O is.

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4. Maths Skills (notes booklet p24)

Task 1

1. With examples, describe what is meant by the following terms:

a) Standard form (3)

b) Significant figures (2)

c) Decimal places (2)

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2. For each of the following numbers, give the number of significant figures and

the number of decimal places that the number is quoted to: (8)

Number

Significant Figures

Decimal Places

1.234

0.01234

0.1012

0.10

0.00001

0.000100001

100

10.

3. Convert each of the following numbers into standard form: (3)

Number

Standard Form

0.00132

0.1034

13200

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4. Convert each of the following numbers from standard form: (2)

Standard Form

Number

6.02 x 10-4

1.0 x 103

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Task 2

1. Complete the following table (use standard form where appropriate): (17)

UNIT VALUE

Tm 2.5 6 x 10-16 0.334

Gm 1 x 10-10 2500

Mm 1 x 10-7 6 x 10-10 334 000

km 6 x 10-7

m 0.1 3.34 x 1011

cm 10 2.5 x 1014 0.06

mm 100 3.34 x 1014

µm 2.5 x 1018

nm 1 x 108 6 000 00

2. The radius of a chlorine atom is 1 x 10-10 m and the radius of a silicon atom is

0.060 nm. Which atom is bigger? Explain your answer with working.

…………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………… (1)

3. Sodium atoms have a radius of 0.180 nm. The nucleus of an atom is about 10

000 times smaller. Estimate the radius of the nucleus of a sodium atom in:

a) nanometres

……………………………………………………………………………………………….

b) metres

……………………………………………………………………………………………(2)

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4. A copper atom has a diameter of 0.256 nm. A copper wire has a diameter of

0.044 cm.

a) Write 0.044 cm in standard form.

…………………………………………………………………………………………....(1)

b) How many times wider is the copper wire compared than a copper atom?

Give your answer to 3 significant figures and explain your answer with working.

…………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………… (2)

5. A gold atom has a diameter of 0.270 nm. The largest gold bar in the world is

45.5 cm long. How many gold atoms fit into 45.5 cm? Give your answer to the

nearest whole number and explain your answer with working.

…………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………… (2)

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Task 3

1. The radius of a hydrogen atom is approximately 0.053 nm. State this

measurement in the following units: (3)

Unit Value

Gm

m

µm

2. Oxygen atoms have a radius of approximately 4.8 x 10-11 m. The nucleus of an

atom is about 10 000 times smaller than the size of the atom. Estimate radius

of the nucleus of an oxygen atom in the following units: (3)

Unit Value

m

km

Tm

3. Magnesium and gold are metals. Magnesium metal is made of magnesium

atoms and gold metal is made of gold atoms.

a) Magnesium atoms have a diameter of approximately 0.145 nm. If a piece of

magnesium had 6.02 x 1023 atoms in it, how long would the piece of magnesium

be, in m, if the atoms joined together in a line? Show your working.

…………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………(2)

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b) A gold atom is approximately 1.74 x 10-8 cm in size. Is this bigger or smaller

than a magnesium atom? Explain your answer.

…………………………………………………………………………………………………………………………

……………………………………………………………………………………………………………………(2)

4. Carbon dioxide is a gas made from little particles of one carbon and two

oxygen atoms, CO2. Carbon atoms have a radius of approximately 6.7 x 10-17

Mm and oxygen atoms have a radius of approximately 4.8 x 10-8 mm.

a) What are the atomic sizes in nm?

i) carbon ……………………………..

ii) oxygen ……………………………. (2)

b) Which atom is smaller?

……………………………………………………………………………………………(1)

c) What is the approximate total radius, in km, of a carbon dioxide particle?

Show your working.

…………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………(2)