A solid begins to melt when?

• A. constituent particles acquires a greater kinetic energy
• B. energy of vibration of particles of the solid is less than the intermolecular forces
• C. constituent particles acquires energy above the average kinetic energy
• D. energy of vibration of particles of the solid equals the intermolecular forces

A mixture of iron and sulphur can be separated by dissolving the mixture in?

• A. steam
• B. dilute hydrochloric acid
• C. dilute sodium hydroxide
• D. benzene

On cracking medicinal paraffin, a gas is evolved which gives a pop sound with a lighted splinter and an oily liquid which decolourizes bromine solution is also obtained. The products of the cracking are ?

• A. carbon (IV) oxide and alkyne
• B. carbon (ll) oxide and alkene
• C. hydrogen gas and alkene
• D. hydrogen gas and alkane

90.0g of MgCI2 was placed in 50.0cm3 of water to give a saturated solubility of the salt is 8.0 mol dm3 at the same temperature, what is the mass of the salt left undissolved at the given temperature? (Mg = 24, Cl = 35.5)

• A. 52.0g
• B. 58.5g
• C. 85.5g
• D. 88.5g

Which of the following is observed when a solution of iron (III) chloride is mixed with a solution of sodium hydroxide?

• A. A gas is evolved
• B. A deep blue precipitate is formed
• C. The resultant solution turns green turns
• D. A brown precipitate is formed

Which of the following is true concerning the properties of benzene and hexane?

• A. Both undergo substitution reaction
• B. Both undergo addition reaction
• C. Both are solids
• D. Both can decolourized bromine water

Which of the following electron configurations indicates an atom with the highest ionization energy?

• A. 2,8,7
• B. 2,8,8,1
• C. 2,8,8,2
• D. 2,8,8,7

A solution containing chloride ions gives white precipitate with silver trioxonitrate(V) Solution. The precipitate will be insoluble in dilute?

• A. HNO₃ but soluble in ammonia solution
• B. HNO₃ and ammonia solution
• C. HCl but soluble in ammonia solution
• D. HCl and in ammonia solution

Soap lather is an example of a colloid in which a?

• A. liquid is dispersed in gas
• B. solid is dispersed in liquid
• C. gas is dispersed in liquid
• D. liquid is despersed in liquid

The oxide that remains unchanged when heated in hydrogen is?

• A. CuO
• B. Fe2O₃
• C. PbO₂
• D. ZnO