(i) Name the process involved in this experiment

DIFFUSION

(ii) State the type of particles• Ion

(iii) Explain the observation in this experiment based on the kinetic theory of matter. 1. Potassium manganate (VII) is made of tiny and discrete

particles/ions 2. The particles are constantly moving/vibrate and rotate 3. The particles move into spaces between agar particles// there are spaces between agar particles// the particles move from high concentration area to low concentration region

(i)Name one subatomic particles present in the nucleus of carbon atom.

Proton // neutron

Atoms that have the same proton number but difference nucleon number.

8

(iv) State one use of cabon-14

To estimate the age of fossil

(a) (i) Write the electron arrangement of magnesium ion

2.8

(ii) State the position of magnesium in the Periodic Table of ElementsGroup 2, Period 3

(b) What is the physical state of chlorine at room condition?

Gas

(c) Which element forms an acidic oxide?

Chlorine / Cl

(d) Aluminium reacts with oxygen to form aluminium oxide. (i) Write the chemical formula of aluminium oxide.

(ii) State the type of bond in aluminium oxide.

Al2O3

Ionic bond

(e) 2.4 g magnesium reacts with chlorine to form 9.5 g magnesium chloride. Determine the empirical formula of magnesium chloride. [Relative atomic mass : Mg = 24, Cl = 35.5]

Mg Clmass 2.4 g 7.1 gmol 0.1 0.2ratio 1 2

(a) Copper(II) nitrate is a salt. State the meaning of salt

ionic compound formed when the hydrogen ion from an acid is replaced by a metal ion or ammonium ion

(ii) State the colour of copper(II) nitrate

(b) In Reaction I, copper(II) nitrate is heated strongly to form solid X, gas Y and gas Z. (i) Name gas Y

Blue

oxygen

(ii) Write the chemical formula of gas Z.

NO2

4. Diagram 4 shows the apparatus set-up for an experiment to determine the heat of displacement.

Based on the experiment, (a)State the meaning of heat of displacement.

Heat change / released when one mole of copper is displaced from/ copper(II) sulphate solution by zinc

(b) Give one reason why polystyrene cup is used in the experiment.

Polystyrene is a heat insulator / / to reduce heat loss to surroundings

(c) The thermochemical equation below represents the displacement reaction.

Zn + CuSO4 ZnSO4 + Cu ΔH = Δ210 kJ mol-1

Calculate: (i)the number of moles of copper(II) ion.

(ii) the heat released during the reaction.

No of moles of Copper(II) ion = 0.2 x 50 // 0.01 mol 1000

1. 1 mol of Cu is displaced produce 210 kJ heat 2. 0.01 mol of Cu = 0.01 x 210 kJ // 2.1 kJ/2100 J

(iii) the change of temperature in the experiment. [Specific heat capacity of solution = 4.2 J g-1 oC-1; Density of solution = 1

g cm-3]

2100 J = 50 x 4.2 x Ɵ // Ɵ = 10oC

(d) The experiment is repeated using magnesium powder to replace zinc powder. The volume and concentration of copper (II) sulphate used is remained the same.

(i) Predict the heat of displacement for the reaction.

More than -210 kJ mol-1 / Higher / Increases

(ii) Give a reason for your answer in 4(d)(i).

Magnesium is more electropositive than zinc // magnesium is higher than zinc in electrochemical series // distance between Mg – Cu is further than Zn-Cu in electrochemical series

(e) Draw the energy level diagram for the reaction

1. Label energy and diagram has 2 different energy levels for exothermic reaction 2. Balanced chemical / ionic equation, ΔH is written

5.Diagram 5.1 and Diagram 5.2 shows the apparatus set-up to investigate the factor that affects the rate of reaction.

(a) (i) Name gas Y.

(ii) Describe a chemical test to verify gas Y. Hydrogen

Place/ insert a lighted splinter into a test tube Produce ”pop” sound

• (b) (i) Calculate the average rate of reactions for Experiment I and Experiment II.

Experiment 1:

Experiment II: Average rate of reaction: = 35/ 140 cm3s-1 or 0.25 cm3s-1

Average rate of reaction: = 35/120 cm3s-1 or 0.29 cm3s-1

(ii) Compare the rate of reaction of Experiment I and Experiment II.

Rate of reaction in Experiment II is higher

(iii) Explain the answer in 5(b)(ii) with reference to the collision theory.

In Experiment II ,

1. Size of zinc in is smaller// Total surface area of zinc in Experiment II is bigger 2. Frequency of collision between zinc atom and hydrogen ion is higher 3. Frequency of effective collisions between zinc atom and hydrogen ion is higher

(c) Sketch the graph of volume of gas Y produced against time for both experiments on the same axes.

Volume of gas Y (cm3)

Time ( s) 1. Correct shape of graf and smooth 2. Label the curve correctly

6 (a) Diagram 6 shows the apparatus set-up to study the displacement of halogen between bromine water and potassium iodide solution.• 1,1,1-trichloroethane is added into the mixture and shaken thoroughly.

(i)State the function of bromine water.

oxidizing agent / to oxidize iodide ion

(ii) State one observation after 1,1,1-trichloroethane is added to the mixture.

(iii) Write the ionic equation for the reaction.

Purple layer formed

Br2 + 2I- 2Br– + I2

1. First mark for correct formulae of reactants and products 2. Balanced the equation

(iv) State the change in the oxidation number of iodine.

(v) Name another reagent that can replace bromine water –1 0

Chlorine r: Fluorine

(b) An experiment is carried out to study the reactivity of metals with oxygen.

(i) Draw the diagram of the apparatus set-up for the experiment

1. Functional diagram

2. Label; Potassium manganate(VII), glass wool, metal

Potassium manganate(VII)

Metal powder Glass wool

Heat Heat

(ii) Suggest metal W.

(iii) Based on your answer in 6(b)(ii), Write the chemical equation for the reaction between metal W and

oxygen

Zinc / Zn

2Zn + O2 2ZnO

(iv) Based on the observations, arrange metals W, X and Y in descending order of the reactivity towards oxygen.

Y, W , X

m