Question

An unsaturated hydrocarbon having two carbon atoms was made to react with two moles of hydrogen gas in the presence of a catalyst to give a saturated hydrocarbon. Using the above information, answer the following questions.
(a) The type of reaction that occurred is __________ (addition / substitution)
(b) Name a suitable catalyst which is used in the reaction
(c) Write a balanced chemical equation for the above reaction

Hint:

If the hydrocarbon had only reacted with one mole of hydrogen, the starting material would have been Ethene (C_2H_4)!

Answer 1

(a) Addition: Since the hydrocarbon is unsaturated (contains multiple bonds) and reacts with hydrogen to become saturated without losing any atoms, it is an addition reaction.

(b) Catalyst: Suitable catalysts include Nickel (Ni), Platinum (Pt), or Palladium (Pd).

(c) Balanced Chemical Equation: Since the hydrocarbon has 2 carbon atoms and reacts with two moles of H_2, the starting material must be Ethyne (C_2H_2). [ C_2H_2 + 2H_2 xrightarrowNi, 200^circtextC C_2H_6 ] (Ethyne reacts with two moles of Hydrogen to form Ethane).