Question 44
Rates of Reaction4 g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q. Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?
- A.There were more aluminium atoms in Q than P.
- B.The heat given off in P retarded the reaction
- C.Q generated more pressure than P during the reaction
- D.P generated more pressure than Q.
- E.Q has a greater surface area for the reaction than P.
Show the answer and explanation
Answer: E (Q has a greater surface area for the reaction than P.)
Explanation
Both flasks held the same mass of aluminium, but powder exposes far more surface to the alkali than foil, so Q reacted faster even though it was cold.