Kimia

Explanation 2 marks

State the manipulated variable and the responding variable in this experiment.

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Explanation 2 marks

Calculate the average rate of reaction for this experiment in cm³ s⁻¹, showing your working.

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Explanation 3 marks

Give the operational definition of the rate of reaction in this experiment, and explain why the marble chips are used in excess.

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Explanation 3 marks

Using the pattern in the results, predict the time taken to collect 40 cm³ of gas when 4.0 mol dm⁻³ hydrochloric acid is used, and compare the fina...

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Explanation 3 marks

State the manipulated variable, the responding variable and one controlled (fixed) variable in this experiment, and explain what each one means.

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Explanation 4 marks

State the trend shown by the results, complete the table by calculating the rate of reaction (1 divided by time) for each concentration, and make a...

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Evaluation 10 marks

Plan a complete laboratory experiment to investigate how temperature affects the rate of reaction between sodium thiosulphate solution and dilute h...

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Explanation 1 mark

Write the formula of the ion formed when a calcium atom loses its valence electrons.

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Explanation 1 mark

Name the type of chemical bond formed between potassium and bromine in potassium bromide.

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Explanation 1 mark

State the oxidation number of chlorine in magnesium chloride, MgCl₂.

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Explanation 2 marks

Calculate the number of moles of zinc atoms in 13.0 g of zinc. [Relative atomic mass: Zn = 65]

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Explanation 3 marks

Explain why metal J must be stored in a bottle of paraffin oil.

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Explanation 4 marks

Describe what is observed when a piece of metal J is burned in oxygen, and deduce the pH of the solution formed when the product is dissolved in wa...

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Evaluation 7 marks

For the magnesium-copper chemical cell, identify the negative terminal and, using electron transfer, explain the oxidation and reduction taking pla...

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Evaluation 8 marks

Metal L (plain iron) and metal M (galvanised iron) are left outdoors for two weeks in humid weather. Metal L becomes covered in brown rust while me...

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Explanation 2 marks

State two observations expected at the electrodes during this electrolysis.

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Explanation 2 marks

State two observations expected in this experiment, and give the operational definition of 'iron is more reactive than copper'.

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Explanation 3 marks

State the manipulated variable, the responding variable and one controlled (fixed) variable in this experiment.

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Explanation 3 marks

Give the operational definition of the cell voltage (potential difference) in this experiment, and predict how the reading would change if tin (les...

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Explanation 3 marks

Calculate the change in mass of each electrode, and suggest one way to improve the accuracy of these mass readings.

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Explanation 3 marks

State the trend shown by the results and make an inference about the reactivity of the metals. Identify which metal is the negative terminal in eac...

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Evaluation 10 marks

Plan a complete experiment to arrange the metals magnesium, zinc, iron and lead in order of reactivity by measuring the voltage of the voltaic cell...

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Explanation 1 mark

Name the gas released when dilute hydrochloric acid reacts with calcium carbonate marble chips.

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Explanation 2 marks

In the reaction, 48 cm³ of carbon dioxide gas is collected in 40 s. Calculate the average rate of reaction, in cm³ s⁻¹.

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Explanation 3 marks

Using collision theory, compare the rate of reaction in Set I and Set II and explain the difference.

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Explanation 3 marks

Without changing the temperature of the water, state one method to dissolve the lump sugar at a higher rate and explain your answer.

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Explanation 4 marks

Predict what would happen to the rate of reaction in Set I if the mixture were gently warmed, and explain your prediction using collision theory.

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Explanation 1 mark

State the colour change seen when a strip of blue litmus paper is dipped into dilute sulfuric acid.

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Explanation 1 mark

Write the chemical formula of ethanoic acid.

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Explanation 1 mark

Write the chemical formula of the salt formed when hydrochloric acid is neutralised by sodium hydroxide solution.

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Explanation 2 marks

Calculate the volume, at room conditions, occupied by 0.25 mol of carbon dioxide gas. [Molar volume = 24 dm³ mol⁻¹ at room conditions]

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Explanation 2 marks

Calculate the concentration, in mol dm⁻³, of a sodium hydroxide solution that contains 4.0 g of sodium hydroxide dissolved in 500 cm³ of solution. ...

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Explanation 3 marks

In a titration, 25.0 cm³ of sodium hydroxide solution is exactly neutralised by 20.0 cm³ of 0.10 mol dm⁻³ hydrochloric acid. Calculate the concentr...

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Explanation 3 marks

Both acids are then prepared at the same concentration of 0.01 mol dm⁻³. Deduce which acid has the lower pH value and explain your answer.

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Explanation 3 marks

Explain the difference between acid A (a strong acid) and acid E (a weak acid) in terms of ionisation.

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Explanation 4 marks

The neutralisation reactions are exothermic. Deduce which of the two acids, A or E, gives the greater temperature rise when neutralised by the same...

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Evaluation 7 marks

Acid A is neutralised by (i) sodium hydroxide and (ii) aqueous ammonia. Compare and explain the heat of neutralisation obtained in the two cases, a...

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