Further Suggested Practical: Laboratory cracking crude oil

What is the primary purpose of the experiment demonstrated?

• To synthesize long-chain alkanes from shorter ones.

• To break down long-chain alkanes into shorter-chain alkanes and alkenes.

• To test the flammability of various hydrocarbons.

• To demonstrate the properties of mineral wool as an absorbent.

What is the function of the pumice stone or broken plant pot pieces in this experiment?

• To absorb excess liquid paraffin.

• To act as a heat source for the reaction.

• To provide a large surface area for the cracking reaction.

• To prevent suckback of water into the boiling tube.

Why is it important to remove the delivery tube from the water before stopping the heating of the boiling tube?

• To prevent the test tubes from overheating.

• To avoid water being sucked back into the hot boiling tube, which could cause it to crack.

• To ensure all gaseous products are collected.

• To allow the catalyst to cool down slowly.

Which chemical is used to test for the presence of alkenes in the collected gas?

• Acidified potassium permanganate.

• Liquid paraffin.

• Mineral wool.

• Water.

Give an alternative chemical test for the presence of an alkene