1. Preparation of Salts

2. What is a salt?
A compound formed when the hydrogen ions of an acid are partly or completely replaced by a positive ion (usually a metal).
Hence a salt will contain a positive metal ion (or ammonium ion) and a negative non-metal ion.
Examples of salts are: sodium chloride, zinc sulphate, copper sulphate.

3. Na+ could come from sodium hydroxide, NaOH (aq)
What is a salt?
Na+ could come from sodium hydroxide, NaOH (aq)
NaCl
Sodium Chloride
Cl- comes from hydrochloric acid, HCl (aq)
HCl(aq) + NaOH(aq)  NaCl(aq) + H2O(l)
Formed when the sodium ion replaces the hydrogen ion of hydrochloric acid

4. H2SO4(aq) + Zn(OH)2(aq)  ZnSO4(aq) + 2H2O(l)
Another example
SO42- comes from sulphuric acid, H2SO4 (aq)
Zn2+ could come from zinc hydroxide Zn(OH)2 (aq)
ZnSO4
Zinc sulfate
H2SO4(aq) + Zn(OH)2(aq)  ZnSO4(aq) + 2H2O(l)
Formed when the zinc ion replaces the hydrogen ions of sulphuric acid.

5. HNO3(aq) + KOH(aq)  KNO3(aq) + H2O(l)
Another example
K+ could come from potassium hydroxide,
KOH (aq)
NO3- comes from nitric acid,
HNO3 (aq)
KNO3
Potassium nitrate
HNO3(aq) + KOH(aq)  KNO3(aq) + H2O(l)
Formed when the potassium ion replaces the hydrogen ions of nitric acid.

6. Acids Acids can donate one or more protonss:
Monoprotic: One hydrogen atom
Example: HCl, HNO3 These donate one proton
Diprotic: Two hydrogen atoms
Example: H2SO4, H2CO3 These donate two protons
Triprotic: Three hydrogen atoms
Example: H3PO4 These donate three protons

7. Preparation of Salts Reactions with acids. Acid + metal Acid + alkali
H2SO4(aq) + Zn(s)  ZnSO4(aq) + H2(g)
Acid + base
H2SO4(aq) + ZnO(s)  ZnSO4(aq) + H2O(l)
Acid + alkali
H2SO4(aq) + Zn(OH)2(aq)  ZnSO4(aq) + 2H2O(l)
Acid + carbonate
H2SO4(aq) + ZnCO3(s)  ZnSO4(aq) + CO2(g) + H2O(l)

8. 23/04/2017

9. 2HCl(aq) + BaO(s) g BaCl2(aq) + H2O(l)
(c) Hydrochloric acid reacts with solid barium oxide, BaO, and barium carbonate, BaCO3.
For each reaction, write a balanced equation (with state symbols) and state what you would see.
BaO
Equation
Observation
2HCl(aq) BaO(s) g BaCl2(aq) + H2O(l)
White solid dissolves away
(ii) BaCO3
Equation
Observation
2HCl(aq) BaCO3(s) g BaCl2(aq) +CO2(g) + H2O(l)
Bubbles of gas given off/White solid dissolves away