Which of these solutions will give a white precipitate with a solution of barium chloride acidified with hydrochloric acid?

• A. Sodium trioxocarbonate (IV)
• B. Sodium tetraoxosulphate (IV)
• C. Sodium trioxosulphate (IV)
• D. Sodium sulphide

SO3 is NOT directly dissolved in water in the preparation of H2SO4 by the contact process because?

• A. the reaction between SO3 and water is violently exothermic
• B. acid is usually added to water and never water to acid
• C. SO3 does not dissolve in water readily
• D. SO3 is an acid gas

One mole of a hydrocarbon contains 48 g of carbon. If it vapour density is 28, the hydrocarbon is?

• A. an alkane
• B. an alkene
• C. an alkyne
• D. aromatic (C = 12, H = 1)

For a gas, the relative molecular mass is equal to 2Y. What is Y?

• A. The mas of the gas
• B. The vapour density of the gas
• C. The volume of the gas
• D. The temperature of the gas

In an electrolytic set-up to protect iron from corrosion, the iron is?

• A. made cathode
• B. made anode
• C. used with a metal of lower electropositive potential
• D. initially coated with tin

A pure solid usually melts?

• A. over a wide range of temperature
• B. over a narrow range of temperature
• C. at a lower temperature than the impure one
• D. at the same temperature as the impure one

Which of the following compounds is NOT an isomers of 2,2 dimethylbutane?

• A. 2-methylbutane
• B. 3-methylpentane
• C. 2,3-dimethylbutane
• D. 2-methylpentane

An anhydride is an oxide of non-mental?

• A. which will not dissolve in water
• B. whose solution in water has a pH greater than 7
• C. whose solution in water has a pH less than 7
• D. whose solution in water has a pH of 7

A solid that absorbs water from he atmosphere and forms an aqueous solution is?

• A. hydrophilic
• B. efforescent
• C. deliquescent
• D. hygroscopic

Which of the following is the correct order of decreasing activity of the metals Fe, Ca, Al and Na?

• A. Fe> Ca> Al> Na
• B. Na> Ca> Al> Fe
• C. Al> Fe> Na> Ca
• D. Ca> Na> Fe>, Al