If a current of 1.5 A is passed for 4.00 hours through a molten tin salt and 13.3g of tin is deposited, what is the oxidation state of the metal in the salt? (Sn = 118.7, F = 96500 C mol-1)

• A. 1
• B. 2
• C. 3
• D. 4

(a) (i) Define saturated solution.

(ii) Tha solubility of KNO\(_3\) at 20°C was 3.00 mol dm\(^{-3}\) If 67.0g of KNO\(_3\) was added to 250 cm\(^{-3}\) of water and stirred at 20°C, determine whether the solution formed was saturated or not at that temperature. [ KNO\(_3\) = 101.0 ]

(b) (i) Distinguish between dative bond and covalent bond.

(ii) Explain why sugar and common salt do not conduct electricity in the solid state.

(iii) State the type of intermolecular forces present in: I. hydrogen fluoride; II argon.

(iv) Consider the compounds with the following structures. S - H ---- N and O - H ---- N In which of the compounds is the hydrogen bond stronger? Give reason for your answer.

(c) (i) State Dalton's Law of Partial Pressure.

(ii) If 200cm of carbon (IV) oxide were collected over water at 18°C and 700 mmHg, determine the volume of the dry gas at s.t.p. [ standard vapour pressure of water at 18°C = 15 mmHg]

Which of the following statements best explains cracking? It is a process

• A. in which an alkene adds on itself repeatedly to form long-chain polymers.
• B. in which large hydrocarbon molecules are broken into smaller units.
• C. for measuring the octane number of petrol.
• D. in which carbon chain results in a zig-zag arrangement

The number of atoms present in 2.5moles of a triatomic gas is equivalent to [1mole = 6.02×10²³]

• A. 2.5×10²³
• B. 1.5×10²³
• C. 1.5×10²⁴
• D. 2.5×10²⁴

The species with no electron in the 3d-orbital is

• A. Zn²⁺
• B. Sc³⁺
• C. Cu
• D. Mn

Which of these gases can be dried with concentrated H2SO4?

• A. HBr
• B. H2S
• C. NH3
• D. SO2

Which of the following elements can conveniently be placed in two groups in the periodic table ?

• A. Carbon
• B. Copper
• C. Hydrogen
• D. Oxygen

Which of the following is TRUE of Le Chatelier's Principle for an exothermic reaction?

• A. Increase in temperature will cause an increase in the equilibrium constant
• B. Increase in temperature will cause a decrease in the equilibrium constant
• C. Addition of a catalyst will cause an increase in the equilibrium constant
• D. Addition of a catalyst will cause a decrease in the equilibrium constant

How many grams of bromine will be required to completely react with 10 g of propyne? (C = 12, H = 1, Br = 80)

• A. 20 g
• B. 40 g
• C. 60 g
• D. 80 g

In metallic colids, the forces of attraction are between the mobile valence electrons and

• A. atoms
• B. neutrons
• C. the negative ions
• D. positively charged nuclei