Which of the following substances has the lowest vapour density? (O = 16, Cl = 35.5, H = 1, C = 12).

• A) ethanoic acid
• B) propanol
• C) dichloro methane
• D) ethanol

The colour of phenolphthalein indicator in alkaline solution at the end-point of an acid-base titration is

• A. colourless
• B. orange
• C. pink
• D. yellow

The furring of kettles is caused by the presence in water of

• A) calcium hydrogentrioxocarbonate (IV)
• B) calcium trioxocarbonate (IV)
• C) calcium tetraoxosulphate (VI)
• D) calcium hydroxide

Consider the following reaction equation: 2HCl+Ca(OH)2→CaCl2+H2O. What is the volume of 0.1moldm−3 HCl that would completely neutralize 25cm3 of 0.3moldm−3 Ca(OH)2?

• A. 150cm3
• B. 75cm3
• C. 30cm3
• D. 25cm3

Classify each of the following as physical change or a chemical change:

(a) fractional distillation of liquefied air;

(b) cracking of petroleum fractions;

(c) conversion of rhombic sulphur to monoclinic sulphur;

(d) chromatographic separation of chlorophyll.

Chemicals that are produced in small quantities and with very degree of purity are

• A. Bulk chemicals
• B. Fine chemicals
• C. Heavy chemicals
• D. Light chemicals

In which of the following processes is biotechnology not applied?

• A. Manufacture of drugs
• B. Treatment of domestic sewage
• C. Production of alcoholic beverages
• D. Electroplating of metals

If 100cm³ of oxygen pass through a porous plug is 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is? [O = 16, H = 1]

• A) 10.0s
• B) 12.5s
• C) 17.7s
• D) 32.0s

The purity of a solid sample can best be determined by its

• A. boiling point
• B. melting point
• C. conductivity
• D. solubility

The electron configuration of two elements with similar chemical properties are represented by?

• A. 1s22s22p5 and 1s22s22p4
• B. 1s22s22p4 and 1s22s22p63s1
• C. 1s22s22p63s1 and 1s22s1
• D. 1s22s22p4 and 1s22s1