In the periodic table, alkaline earth metals can be found in group

• A. l
• B. ll
• C. VI
• D. VII

A colourless hydrocarbon with a sweet smell undergoes substitution reaction. The hydrocarbon is likely to be

• A. alkanol
• B. benzene
• C. ester
• D. methane

In the reaction E+F ↔ G+H, the backward reaction is favoured if the concentration of

• A. F is increased
• B. E is increased
• C. E is reduced
• D. G is reduced

(a) i) Give the name and nature of the radiations that are emitted during radioactivity.

ii) State two differences between chemical reaction and nuclear reaction.

iii) Balance the following nuclear reactions and identify X and Y.

I. \(^{212}_{84} PO\) \(\to\) \(^{208}_{82} Pb\) + X

II \(^{137}_{55}Cs\) \(\to\) \(^{137}_{55}Ba\) + Y

(b) The electron configuration of an element X is: 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^5\)

(i) Deduce the atomic number of X.

(ii) To what group does X belong?

(iii) Give two properties of the group to which the element X belong.

(iv) Identify element X by name.

(v) Write a balanced equation to represent the reaction between the element X and hot concentrated NaOH.

(c)(i) Explain why: I. graphite is used as a lubricant; II. diamond is used as an industrial cutting tool.

(ii) Write an equation to represent the reaction between aqueous HCI and NH\(_3\) solution.

(iii) Name the type of reaction represented by the equation.

Which of the following metals is the least reactive?

• A) Pb
• B) Sn
• C) Hg
• D) Au

Which of the following pairs of reagents reat to produce hydrogen?

• A. Zinc and concentrated trioxonitrate (V) acid
• B. Water and calcium dicarbide
• C. Copper and dilute hydrochloric acid
• D. Magnesium and dilute tetraoxosulphate (VI) acid

Nitrogen obtained from the liquefaction of air has,a higher density than that obtained from nitrogen containing compounds because the former contains

• A) water vapour
• B) oxygen
• C) carbon (iv) oxide
• D) rare gases

(a) If L is the Avogadro constant and E° is standard cell potential, state what X and Y stand for in the following expressions

(i) X = \(\frac{\text{Mass of L molecules of gas or vapour}}{\text{ Mass of L molecules of hydrogen}}\)

(ii) Y = -nFE°

(b) State two differences between a primary cell and a secondary cell.

The fourteen elements (atomic number 90-103) after actinium are called?

• A. Actinoids
• B. Nucleotides
• C. Pre-actinum elements
• D. Atomic elements

Chlorine gas turns a damp starch-iodide paper

• A. pink
• B. colourless
• C. red
• D. dark blue