Question

Using the activity series, write balanced chemical equations for the following reactions. If not reaction occurs, simply write NR.
(a) Nickel metal is added to a solution of copper(II) nitrate
(b)A solution of zinc nitrate is added to a solution of magnesium sulfate.
(c) hydrochloric acid is added to gold metal
(d) chromium metal is immersed in an aqueous solution of cobalt(II) chloride
(e) hydrogen gas is bubbled through a solution of silver nitrate

Answer 1

Answer:

a) $2 Ni (s) + Cu(NO_3)_2 (aq) \longrightarrow Cu(s) + 2 NiNO_3 (aq)$

b) NR

c) NR

d) $2 Cr (s) + 3 CoCl_2 (aq) \longrightarrow 3 Co(s) + 2CrCl_3 (aq)$

e) NR

Explanation:

a) Nickel is more reactive than copper so the first one will displace the other:

$2 Ni (s) + Cu(NO_3)_2 (aq) \longrightarrow Cu(s) + 2 NiNO_3 (aq)$

b) Due to the higher reactivity the magnesium has compared to the zinc, the first will remain in solution and the second will reamin solid. So, NR.

c) No reaction occurs, gold is resistant to acid in normal conditions due to its characteristic as noble metal.

d) Chromium is more reactive than cobalt so the last one will be displaced:

$2 Cr (s) + 3 CoCl_2 (aq) \longrightarrow 3 Co(s) + 2CrCl_3 (aq)$

e) Nothing happens, the reduction potencial of the hydrogen gas bubbled ins't enough to reduce the silver.