Reactions of acids
4 marks · NormalAnswer the following about acids and bases.
State the definition of an acid in terms of proton transfer.
State the definition of a base in terms of proton transfer.
Ammonia reacts with hydrochloric acid to form ammonium chloride. Write an equation for the reaction and identify which species acts as the proton donor.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) An acid is a proton (H+) donor.
(b) A base is a proton (H+) acceptor.
(c) NH3 + HCl -> NH4Cl; HCl acts as the proton donor. · must show NH3 + HCl -> NH4Cl, HCl is proton donor
Common mistakes: Confusing acid/base with electron transfer; incorrect equation.
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Marking points
B1 (a) · 1 mark · Correctly defines acid as a proton donor (accept H+ donor).
B2 (b) · 1 mark · Correctly defines base as a proton acceptor (accept H+ acceptor).
M1 (c) · 1 mark · Gives correct equation: NH3 + HCl -> NH4Cl
B3 (c) · 1 mark · Identifies HCl as the proton donor in reaction.
Worked solution
a) An acid is a proton (H+) donor.
b) A base is a proton (H+) acceptor.
c) The equation:
HCl acts as the proton donor (gives a proton to NH3).