Which of the following compounds is used as a gaseous fuel?

• A) CH3 -CH2 -CHO2 -COOH
• B) CH3 -C = CH
• C) CH3 -CH2 -CH2 -CH3
• D) CH2 -CH2 -CH3

Organic molecules that have the suffix -ene are unsaturated hydrocarbons that have

• A) a single bond
• B) a double bond
• C) a triple bond
• D) an ionic bond

When naphthalene on heating changes from the solid state directly to the gaseous state it undergoes

• A. evaporation
• B. sublimation
• C. decomposition
• D. combustion

The gas that is used for the treatment of cancer is

• A) Neon
• B) Radon
• C) Xenon
• D) Argon

Consider the compounds represented by the following general formula: X₂SO₄ Y₂(SO₄)₃. 24H₂O X and Y could respectively be

• A. K and AI
• B. Fe and K
• C. AI and Fe
• D. AI and K

(a)(i) Explain what is meant by saturated solution

(ii) Describe in outline, a suitable procedure for preparing a saturated solution of sodium trioxonitrate(V) at 30°C.

(ii) State two techniques that can be used to recover crystals of sodium trioxonitrate(V) from its saturated solution.

(b) 1.0dm\(^3\) of an aqueous solution at 90°C contains 404g of potassium trioxonitrate(V) and 245g of potassium trioxochlorate (V).

(i) Determine which of the two salts will separate out when the solution is cooled to 60°C. N = 14. O = 16, CI = 35.5, K = 39; Solubility of KNO\(_3\) in water at 60\(^o\)C = 5.14 mol.dm\(^{-3}\), Solubility of KCIO\(_3\) in water at 60°C = 1.61 mol.dm\(^{-3}\)

(ii) Calculate the mass of salt that will separate out at 60°C

(c)(i) List two salts which cause hardness of water.

(ii) Explain why temporary hardness of water result in the furring of kettle.

What mass of anhydrous sodium trioxocarbonate(IV) is present in 500cm\(^3\) of 0.1mol dm\(^{-3}\) of the solution [Na = 23, C = 12, O = 16]

• A) 10.6g
• B) 106g
• C) 5.3g
• D) 53g

A given quantity of a gas occupies a volume of 228 cm³ at a pressure of 750mm Hg. What will be its volume at atmospheric pressure?

• A. 220 cm3
• B. 225 cm3
• C. 230 cm3
• D. 235 cm3

In which of the following pairs are both substances deliquescent?

• A. CaCI2 and H2SO4
• B. NaOH and MgSO4 7H2O
• C. CaCI2 and NaOH
• D. CUO and NaCI

a)(i) Give two uses of ammonia.

(ii) Name the process by which ammoniacal liquor can be obtained from coal and list two other products of the reaction

(iii) What type of reaction is involved in the conversion of ammoniacal liquor to (NH\(_4\))\(_2\)SO\(_4\) by dilute H\(_2\)SO\(_4\)?

(iv) Sketch and label an energy profile diagram to show the effect of presence of Pt/Rh on the reaction represented by the following equation: 4NH\(_3\) + 5O\(_2\) \(\to\) 6H\(_2\)O + 4NO; \(\Delta\)H = —907 kJmol\(^1\)

(b) Rock salt is an impure form of sodium chloride.

(i) Outline a suitable procedure for preparing a pure sample of sodium chloride from rock salt.

(ii) State two methods that can be used to prepare chlorine from rock salt. Write an appropriate equation in each case.

(c) Lead pigments were used in a water colour painting which turned black after prolonged exposure to an air pollutant. The original colour was restored by using H\(_2\)O\(_2\) which converted the black substance to a simple, white lead (II) salt.

(i) Which pollutant turned the painting black?

(ii) Write the formula of the black substance

(iii) What is the white salt?

(iv) State the role of H\(_2\)O in the restoration process.