Single Displacement
• Most
Examples:
metals occur naturally as ores (oxides - MgO,
1) CuO(s) + H2SO4(aq)
CuSO4(aq) + H2O(l)
isolate the metals from their ores:
1b) CuSO4(aq) + Fe(s)
FeSO4(aq) + Cu(s)
1) react them with a solution to form an
aqueous salt
2) Ag2S(s) + NaCN(aq)
AgCN(aq) + Na2S(aq)
2b) AgCN(aq) + Zn(s)
Ag(s) + Zn(CN)2(aq)
sulfides, halides, carbonates, sulfates, silicates)
• To
2) replace one element with another (usually
cheaper) in order to isolate the desired metal
Types: Single displacement
Cu
Cl
+ Fe
!
Cl
Fe
Experiments reveal trends. The activity series
ranks the relative reactivity of metals.
It allows us to predict if certain chemicals will undergo single
displacement reactions when mixed: metals near the top are
most reactive and will displacing metals near the bottom.
Example: Fe + CuCl2
Cl
The Activity Series
Cl
+
General: AB + C ! CB + A
Cu
Q: Which of these will
react?
Fe(s)+ CuSO4(aq) ! Cu(s) + Fe2(SO4)3(aq)
Ni(s) + NaCl(aq) !
NR (no reaction)
Li(s) + ZnCO3(aq) !
Zn(s) + Li2CO3(aq)
Al(s) + CuCl2(aq) ! Cu(s) + AlCl3(aq)
Li
K
Ca
Na
Mg
Al
Zn
Fe
Ni
Sn
Pb
H
Cu
Hg
Ag
Au
Halogens:
•As we go down group 7, halogens become
less reactive.
Other Uses for Activity Series
•Anti-Corrosion: Copper plating (lower on the
series = less likely to react)
•Galvanizing: Zinc plating (higher on the series,
fluorine
reacts to form insoluble oxide = protection)
chlorine
bromine
•Alloy: Stainless steel - iron, carbon, chromium,
iodine
So, fluorine will displace chlorine, bromine will displace iodine
SD Examples with Group 1&2 metals
nickel = less reactive (chromium) and harder
(carbon)
Single Displacement Summary
•used widely in/for metallurgy
Li(s) + H2O(l)
Ca(s) + H2O(l)
LiOH(aq) + H2(g)
Ca(OH)2(aq) + H2(g)
•Reactive elements (K, Ba, Ca, Na, Li) react
vigorously with water and acids to produce
H2 (g) and bases (contain OH - hydroxide)
•Reactivity series allows us to create more
resistive materials - galvanizing and alloys
Final Notes (Electronegativity)
• If
you run into a metal (not in your activity
series), look at the electronegativity value Periodic Table
• Metals
with lower electronegativity will usually
displace those with higher electronegativity
Homework
• p. 128, Q
#3, #5, #6
• p. 134, Q
#11