The activation energy of a reaction can be altered by

• A. adding a reducing agent
• B. applying a high pressure
• C. using a catalyst
• D. changing the temperature

Positive ions in a sea of electrons are found in

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

Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth-to-mouth to each other at room temperature. The entropy in the mixture of gases is likely to

• A) remain unchanged
• B) increase
• C) decrease
• D) change

Which of the following compounds determines the octane rating of petrol?

• A. 1,2,3 - trimethlpentane
• B. 2,3,5 - trimethyloctane
• C. 2,3,5 - trimethylpentane
• D. 2,2,4 - trimethylpentane

If an equilibrium reaction has ΔH > 0, the reaction will proceed favourably in the forward direction at

• A. High temperature
• B. Any temperature
• C. Low temperature
• D. Minimum temperature

To what temperature must a gas at 273k be heated in order to double both its volume and pressure?

• A) 298K
• B) 546K
• C) 819K
• D) 1092K

Which of the following occurs when a solution of CuSO₄ is electrolysed using copper electrodes?

• A. The cathode becomes coated with copper
• B. Both electrodes gain electrons
• C. The blue colour of the solution fades gradually
• D. The anode increases in mass

Pipe-borne water is usually chlorinated in order to

• A. improve the teste of the water
• B. remove the hardness in the water clear
• C. coagulate sediments in the water
• D. kill harmful bacteria in the water

(a) State the monomer units of (i) polyethene; (ii) cellulose

(b) Name the two fuels obtained when steam and air are passed over red-hot coke.

Which of the following statement is true of a proton?

• A. The mass of a proton is 1840 times the mass of electron
• B. the total mass of the protons in a particular nucleus is always half the nuclear size
• C. The mass of a proton is one - twelfth the molar mass of carbon
• D. The mass of a proton is 1.0008g