Question in Paper 3 test for 11 Scientific Skills Science Process Skills Science process skills enable students to formulate their questions and find out the answers systematically.Descriptions of the science process skills are as follows: 1. 2. 3. 4. 5. 6. 7. 8. 9. Observing Classifying Measuring and Using Numbers Inferring Predicting Communicating Interpreting Data Defining Operationally Controlling Variables Using the sense of hearing, touch, smell, taste and sight to collect information about an object or a phenomenon. Using observations to group objects or events according to similarities or differences. Making quantitative observations using numbers and tools with standardised units. Measuring makes observation more accurate. Using past experiences or previously collected data to draw conclusions and make explanations of events. Stating the outcome of a future event based on prior knowledge gained through experiences or collected data. Using words or graphic symbols such as tables, graphs, figures or models to describe an action, object or event. Giving rational explanations about an object, event or pattern derived from collected data. Defining concepts by describing what must be done and what should be observed. Identifying the fixed variable, manipulated variable, and responding variable in an investigation. The manipulated variable is changed to observe its relationship with the responding variable. At the same time, the fixed variable is kept constant. Making a general statement about the relationship between a manipulated variable and a responding variable in order to explain an event or observation. This statement can be tested to determine its validity. Planning and conducting activities to test a certain hypothesis. These activities include collecting, analysing and interpreting data and making conclusions.
Questions in Paper 3 are based on experiments. List of Common Experiments Form 4
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
Determine the empirical formula of magnesium oxide and copper (II) oxide Compare the reactivity of Group 1 in the reaction with water Compare the reactivity of Group 17 in the reaction with iron wool Compare the properties of ionic and covalent compund Construct the ECS of metal by using difference potential / voltage of a voltaic cell Relationship between concentration of hydrogen ion and pH value The role of water in showing the properties of acids or alkalis Determine the concentration of sodium hydroxide by using titration method Preparation of soluble salt ( lead (II) chloride) Construct ionic equation Compare the hardness of alloy (brass) and pure metal (copper).
Form 5 1. 2. Factors affecting rate of reaction ( 4 factors) Compare the properties of saturated and unsaturated hydrocarbon. ( Bromination / sootiness of flame) Prepare ester from carboxylic acid and alcohol Effects of acid and alkali on coagulation of latex Compare the elasticity of vulcanized and unvulcanised rubber Displacement of halogen as a redox reaction Transfer of electron at a distance Effects of other metals on rusting of iron Compare the reactivity of some metals in reaction with oxygen
3. 4. 5. 6. 7. 8. 9.
10. 11. 12.
Determine the heat of combustion for different types of alcohols Preparation of soap from palm oil Effectiveness of soap as cleaning agent in hard water
Question Analysis for Paper 3 Trial Chemistry 2012 from Different States No 1 2 3 States Perak SBP Kedah Question 1 Construct ECS based on cell voltage Compare the hardness of pure metal and its alloy Heat of neutralization Question 2 Hardness of pure and alloy Heat of combustion for alcohol Solubility of salt Question 3 Effect of other metals on rusting Effect of other metals on rusting The effect of distance between two metals in ECS on voltage Effect of temperature on the rate of reaction
Relationship between concentration of hydroxide ion and pH value of ammonia solution Effect of other metals on rusting Heat of precipitation
Compare the reactivity of halogen towards their reaction with hot iron Heat of combustion of alcohol Relationship between concentration of hydrogen ion and pH value of an acid
Compare the solubility different type of salt Effect of other metals on rusting
Question Effect of other metals on rusting Heat of reaction ( precipitation, combustion, neutralisation) Cell voltage and Electrochemical Series Hardness of alloy and pure metal Relationship between concentration of acid / alkali and its pH value Solubility of different type of salt
Frequency 4 4 2 2 2 2
Just as a Guideline, not a Prediction !!!
Chemistry Perfect Score Module 2012 (set 3) 2. (a) Diagram 2.1 shows the pH value of glacial ethanoic acid in solvent P and solvent Q respectively.
(i) Suggest solvent P and solvent Q. Solvent P: . Solvent Q: . [2 marks] (ii) If magnesium ribbon is added into beaker containing glacial ethanoic acid and solvent P, what can be observed? [1 mark] (iii) Explain why ethanoic acid in solvent P and solvent Q has different the pH value. . ... [3 marks] (b) Diagram 2.2 shows the concentration of hydrochloric acid in volumetric flask when a certain volume of hydrochloric from the beaker is transferred to the volumetric flask and added with water
(i) What happen to the pH value of the hydrochloric acid when water is added to the acid? Give a reason for your answer. . [2 marks] (ii) Calculate the volume of hydrochloric acid that is needed to prepare 250cm3 of 0.04 mol dm-3 hydrochloric acid. [2 marks]
Chemistry Perfect Score Module 2012 (set 3) 4 Diagram 4 shows the apparatus set-up for the neutralisation reaction between sulphuric acid and potassium hydroxide solution for preparation of salt X.
Diagram 4 (a) (i) State the colour change of the solution in the conical flask at the end point.
.[1 mark] (ii) Write a chemical equation for the above reaction. [2 marks] (iii) Calculate the concentration of potassium hydroxide used. [2 marks]
(b) (i) State the name of salt X. .. (ii) Calculate the maximum mass of salt X formed. [Molar mass of salt X = 174 g mol-1] [3 marks]
(c) (i) The experiment is repeated with 0.1 mol dm-3 nitric acid to replace sulphuric acid. Predict the volume of nitric acid needed to neutralize completely potassium hydroxide .. [1 mark] (iii) Explain your answer in (c) (i). ..................................................................................................................................... .................................................................................................................... [2marks]
Chemistry Perfect Score Module 2012 (set 3) 7. Diagram 7 shows two experiments to investigate one of the factors that affect the rate of reaction between zinc and hydrochloric acid
(a) (i) Based on Diagram 7, state the factor that affect the rate of reaction in this experiment. . [1 mark] (ii) Besides measuring the change of volume of gas released at certain time interval, suggest another measurable change to determine the rate of reaction?
.. [1 mark] (b) In Experiment II, 2.0 cm3 0.5 moldm-3copper(II) sulphate solution is added. The maximum volume of hydrogen gas released in Experiment I is V cm3. (i) Compare the volume of gas released in Experiment I and Experiment II. Give a reason for your answer. .. . [2 marks] (ii) The graph of volume of hydrogen gas released against time in Experiment I is shown below.
Sketch the curve for Experiment II on the same axes in the graph above. [2 marks] (iii) With reference to collision theory, explain how copper (II) sulphate solution affect the rate of reaction in this experiment. .[3 marks] (c) Table 7.1 shows three experiments done by a student. Experiment Reactants A Excess calcium carbonate chips + 25 cm3 1.0 mol dm-3 hydrochloric acid B Excess calcium carbonate chips + 25 cm3 0.5 mol dm-3 hydrochloric acid C Excess calcium carbonate chips + 100 cm3 0.5 mol dm-3 hydrochloric acid The graph of volume of carbon dioxide released against time is sketched as shown in graph 7. Based on the above table and graph, determine which curve represents the results for experiment B and C. Write your answers in the boxes provided.
Chemistry Perfect Score Module 2012 (set 1) 10 (a) Helium, exists as a monoatomic gas whereas chlorine, exists as a diatomic gas. Explain why. [6 marks]
(b) Table 10.1 shows the proton number of magnesium, chlorine and carbon. (b) Table 10.1 shows the proton number of magnesium, chlorine and carbon. Element Proton number Magnesium 12 Table 10.1 Chlorine 17 Carbon 6
(i) Carbon reacts with chlorine to form a compound. What type of the compound formed? Draw the electron arrangement to show the chemical bond in the compound. [3 marks] (ii) Explain how ionic bond is formed between magnesium and chlorine atoms. [7 marks] (c) Diagram 10 shows the set-up of apparatus to investigate the electrical conductivity of naphthalene and sodium chloride solution.
Table 10.2 shows the result of the experiments. Compound Naphthalene Sodium chloride solution Table 10.2 Explain the electrical conductivity of the two compounds. Observation Bulb does not light up Bulb lights up