b. Study the scheme diagram below and answer the questions that follow: (i) Name the reagent that is suitable to carry out the reaction in step (ii) Name the process that takes place in step II. (iii) State the conditions necessary for the reaction in step III to occur. (iv) Name one industrial use for the reaction in step III. (v) Write down the equation for the reaction that takes place in step IV.

Here are the answers to the questions based on the provided reaction scheme:

i) Name the reagent that is suitable to carry out the reaction in step II.
Step II is the polymerization of ethene to poly(ethene). This process requires an initiator to start the reaction.

• Oxygen (or peroxides)

ii) Name the process that takes place in step II.
Step II involves the joining of many ethene monomers to form a long polymer chain.

• Addition polymerization

iii) State the conditions necessary for the reaction in step III to occur.
Step III is the hydrogenation of ethene to ethane. This is an addition reaction where hydrogen is added across the double bond.

• Nickel catalyst and heat (e.g., $150-200^\circ C$)

iv) Name one industrial use for the reaction in step III.
Step III is hydrogenation. Industrially, hydrogenation is used to convert unsaturated fats (oils) into saturated fats (solids).

• Manufacture of margarine (or hardening of vegetable oils)

v) Write down the equation for the reaction that takes place in step IV.
Step IV is the addition of hydrogen chloride to ethene to form chloroethane.

$$CH_2=CH_2(g) + HCl(g) \longrightarrow CH_3CH_2Cl(g)$$