AS CHEMISTRY TRIAL PERIOD TASK ONE
Summer Questions
Section One – The Structure of the Atom
1.
2.
3.
4.
What charge does and oxide ion have and why?
Where is most of the mass in an atom?
Explain why atoms do not have an overall charge
Calculate the number of protons, neutrons and electrons for chlorine35 and chlorine-37
5. What is the symbol of the element with 10 neutrons and 9 electrons?
6. Find the relative atomic mass of lithium if there are 12 atoms of Li-7
to every atom of Li-6.
7. Calculate the relative formula mass for:
a. NaCl
b. CaCO3
c. Mg(OH)2
8. How many particles are there in one mole of a substance?
9. Find the molar mass of nitric acid, HNO3
10. How many moles of calcium are there present in 24g of CaCO3?
11. I have 12g of MgCO3 and 19g of Mg. Do I have more moles of MgCO3
or Mg? Show your working
12. Draw the electron arrangements and the shorthand for F, Cl, Br, He,
Ne and Ar.
13. How could you split these six into two groups without looking at the
periodic table? Explain why
Section Two – Chemical Bonds
14. Decide which block of the periodic table the following elements are in:
a. Lithium
b. Chlorine
c. Silicon
d. Rubidium
e. Aluminium
15. Draw a diagram to show the ionic bonding in CaO
16. Draw a diagram to show the bonding in MgCl2
17. Draw ‘dot and cross’ diagrams to show the bonding in:
a. HCl
b. F2
c. CO2
d. C2H2
Section 3 – Ionic and Covalent Structures
18. If an atom loses one electron what charge will it have?
19. If an atom gains two electrons what charge will it have?
20. In CaCO3 what is the ration of Ca2+ ions to CO32- ions?
21. In lithium oxide what is the ratio of Li+ ions to O2- ions?
22. Explain why ionic compounds do not conduct electricity when solid and
what you can do to them to make them conduct.
23. Explain how ionic compounds dissolve in water in terms of charges
24. Describe the trend in boiling point of the alkanes as the carbon chain
becomes longer
25. Explain why chloromethane has a greater boiling point than methane
26. Why are small covalent molecules insoluble in water and electrical
insulators?
27. Compare the similarities and differences between graphite and
diamond and link these to the different properties of each.
28. Explain the four trends across period 3
Section Four – Hydrocarbon Molecules
29. Why do the shorter hydrocarbon chains come off at the top?
30. What is the name of the process by which a mixture of hydrocarbons
can be separated?
31. Write balanced symbol equations for the complete and incomplete
combustion of:
a. Propane (C3H8)
b. Butane (C4H8)
32. Draw out the following alkanes:
a. Octane (C8H18)
b. Heptane (C7H16)
33. How could you distinguish between an alkene and an alkane?
34. Draw out all the possible structures for octene (C8H16)
35. Define the words monomer and polymer
Section Five – Rates of Reaction
36. List three ways that you can measure the rate of reaction
37. List four ways that you can increase the rate of reaction
38. Explain what a dynamic equilibrium is
39. Explain what a catalyst is
Section Six – Reversible Reactions
40. State Le Chatelier’s Principle
N2(g) + 3H2(g)  2NH3(g)
Exothermic
41. Copy out the above equation and balance it
42. What will happen to the yield of ammonia if you increase the pressure
and explain why?
43. What will happen to the yield of ammonia if the temperature is
decreased and explain why?
44. Why is a compromise of moderate temperature and pressure used?
Section Seven – Symbol Equations
45. Deduce the formula of the following ionic compounds:
a. Potassium chloride
b. Calcium oxide
c. Lithium oxide
d. Calcium nitrate
e. Iron(III)oxide
46. Balance the following symbol equations:
a. ____ NaCl + ____ F2  ____ NaF + ____ Cl2
b. ____ H2 + ____ O2  ____ H2O
c. ____ Pb(OH)2 + ____ HCl  ____ H2O + ____ PbCl2
d. ____ AlBr3 + ____ K2SO4  ____ KBr + ____ Al2(SO4)3
e. ____ CH4 + ____ O2  ____ CO2 + ____ H2O
Section Eight – Calculating Formulae
47. A compound consists of 29.1%Na, 40.5% S, and 30.4% O. Determine
the simplest formula.
48. A compound is composed of 7.20 g carbon, 1.20 g hydrogen, and 9.60 g
oxygen. Find the empirical formula for this compound
49. Calculate the molecular formula for the following:
a. 64.9% C, 13.5% H and 21.6% O
Mr = 74
b. 39.9% C, 6.7% H and 53.4% O
Mr = 60
c. 40.3%, 52.2% H and 7.5% O
Mr = 80
Section Nine – The Periodic Table
50. Find the symbols or names for the following: Helium, Hg, Magnesium,
potassium, Ni, Cl, Ag
51. What is the charge on the ions formed by each of these elements: Li,
calcium, Oxygen, Aluminium and F
Section Ten – Reactivity and the Periodic Table
52. Explain what would happen if you mixed the following halogen and
halide solutions and write an ionic equation for each reaction that
occurs:
a. Chlorine and bromide
b. Bromine and chloride
c. Iodine and bromide
53. Explain why the reactivity of group 2 metals increases down the group
where as the reactivity of group 7 halogens decreases.
Section Eleven – Chemical Reactions
54. Write down all the different types of reaction that each of the
following could be classed as:
a. Burning propane
b. Chlorine + sodium bromide  Sodium bromide + chlorine
c. Calcium carbonate  calcium oxide + carbon dioxide
d. Hydrochloric acid + calcium carbonate  Calcium chloride +
water + carbon dioxide
Section Twelve – Energy and Chemistry
55. Decide whether the following example are exothermic or endothermic
and then explain why you made your choice:
a. Hydrochloric acid and sodium hydroxide
b. Burning Methane
c. Photosynthesis
d. Respiration
e. Methane and steam
56. Calculate how much energy is released in the following reactions using
bond energies.
a. C3H6 + H2  C3H8
b. CH4 + 2O2  CO2 + 2H2O
c. C6H14 + 9½O2  6CO2 + 7H2O
Section Thirteen – How Science Works
57. Write definitions for the following key words when used in the
context of investigations:
a. Independent variable
b. Dependent variable
c. Control variable
d. Mean result
e. Anomalous result
f. Valid
g. Precise
h. Accurate