HKDSE Chemistry Practice Paper Marking Scheme
K c 4 3 2 2 3 4 [Cu (aq)] [NH (aq)] [Cu(NH ) (aq)] + + = 1 (1) (b) (0.002) (0.0014) 4 0.08 K c = = 1.04 × 10 13 (mol dm –3) –4 (1 mark for answer; 1 mark for correct units) 1+1 (2) (c) or, H 2 SO 4 (aq) reacts with the NH 3 (aq) present: H + (aq) + NH 3 (...