Which of the following polymers in thermosetting?

• A. Bakelite
• B. Nylon
• C. Polypropene
• D. Polystyrene

Which of the following reaction is endothermic?

• A. C(s) + O2(g) → CO2(g)
• B. CaO(s) + H2O(l) → Ca(OH)2(s)
• C. C(s) + H2O(g) → CO(g) + H2(g)
• D. HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

Oxygen is extracted from water by

• A) displacement reaction
• B) oxidation reaction
• C) reduction reaction
• D) decomposition reaction

The correct order of increasing boiling points of the following compounds C3H7OH, C7H16 and C4H10 is

• A) C3H7OH → C4H10 → C7H10
• B) C4H10 → C7H16 → C3H7OH
• C) C7H16 → C3H7OH → C4H10
• D) C4H10 → C3H7OH → C7H16

3Cu + pHNO₃ →3Cu(NO)₂ + 4H₂O + xNO In the equation above, the values of p and x respectively are

• A. 1 and 3
• B. 2 and 3
• C. 6 and 2
• D. 8 and 2

The type of chemical bond that exists between potassium and oxygen in potassium oxide is

• A. ionic
• B. metallic
• C. covalent
• D. dative

(a) Give two reasons why carbon(IV) oxide is used for extinguishing fire

(b) Explain briefly the water softening action of cation exchange resins.

Alloys are best prepared by

• A. Electroplating
• B. Arc-welding
• C. Reducing and mixture of their metallic oxide
• D. Cooling a molten mixture of the metals

A mixture of kerosene and diesel oil can be separated by

• A. crystallization
• B. distillation
• C. precipitation
• D. sublimation

In the diagram below, the gas produced is

• A) NO
• B) NO2
• C) N2O
• D) N2O4