Salts

Question 1

What is a salt?

Answer 1

A complex substance which includes metal cations and anions of acidic residues.
May also contain hydroxide or hydrogen ions.

Question 2

What is the classification of salts?

Answer 2

Since salts are the product of complete or partial replacement of an acid by a metal, they can be classified according to their composition as follows:
Acid Salts
Medium salts,
Basic salts
Double salts
Mixed Salts
Complex Salts
and
Hydrate salts

Question 3

What is an Acid Salt?

Answer 3

Salt formed by the incomplete replacement of hydrogen atoms by a metal in an acid.
Examples include:
LiHCO3 - Lithium Bicarbonate
NaHSO4 - Sodium Hydrogen sulfate
NaH2PO4 - Sodium dihydrogen phosphate

Question 4

What are medium salts?

Answer 4

These are salts formed by the complete replacement of hydrogen atoms in an acid with a metal.
Examples include:
CuSO4 - Copper (II) Sulfate
CaCl2 - Calcium Chloride

Question 5

What are basic salts?

Answer 5

These are products of incomplete replacement of hydroxide groups by an acidic residue.
An example includes Mg (OH)Cl.

Question 6

What are double salts?

Answer 6

This is when the composition includes two different metals and one acid residue.
Example
KNaSO4 - Potassium - Sodium Sulfate
KAl(SO4)2 - Potassium-Aluminum Sulfate

Question 7

What are Mixed Salts?

Answer 7

These are salts that contain one metal and two different acidic residues.
Examples include:
CaClOCl- Calcium Chloride-Hypochloride
PbFCl- Lead Fluoride-Chloride

Question 8

What are Complex Salts?

Answer 8

These are formed by complex cations or anions associated with several ligands.
An example includes:
K [AL (OH)4] Potassium tetrahydoxoaluminite

Question 9

What are Hydrate Salts?

Answer 9

These are salts whose composition includes a molecule of crystallization water.
An example includes:
CuSO4.5H20 - Copper (II) sulfate pentahydrate

Question 10

How are medium salts obtained?

Answer 10

They can be formed during the following reactions:

Metal + Non-metal = Salt
Metal on the left of H2 in reactivity + Acid solution=Salt + Hydrogen gas
Metal + Salt solution with less reactive metal= Salt + Metal atom
Basic Oxide + Acid Oxide = Salt
Basic Oxide + Acid =Salt + Water
Base with acidic oxide = Salt + Water
Salt + Acid = Salt + Water/Gas/Acid
Base solution with salt solution = Salt +Hydroxide

Question 11

How are acidic salts obtained?

Answer 11

They can be formed during the following reactions:
Acid + Metal = Salt + Hydrogen gas
Acid + Metal Oxide = Salt + Water
Acid + Metal Hydroxide = Salt + Water
Acid + Salt = Salt
Acid + Ammonia = Salt
Base + excess acid oxide = Acidic salt

Question 12

How are basic salts obtained?

Answer 12

Acid + excess base = Basic Salt + Water
Addition of alkalis to solutions of medium metal salts = Salt + salt
Interaction of weak acids + Medium salts = Basic salt

Question 13

How are complex salts obrained?

Answer 13

This is when a salt reacts with a ligand.

Question 14

How do we make double salts?

Answer 14

These are obtained by the co-crystallization of two salts:

Cr2(SO4)3 + K2SO4 + 24H2O = 2[KCr(SO4)2.12H2O]

Question 15

What are the chemical properties of Medium Salts?

Answer 15

Decompose into ions.
Thermally decompose to produce a gas and salt.
Interact with metals to form a new salt + metal.
Susceptible to hydrolysis.
Performs exchange reactions with acids, bases and between two salts.
Also undergo redox reactions

Question 16

How do ammonia salts decompose?

Answer 16

Decompose to release nitrogen or nitrogen oxide if the anion in the composition exhibits oxidizing properties.
Other times, it may also lead to the release of Ammonia gas.

Question 17

Chemical properties of acid salts.

Answer 17

Complete dissociation
Thermally decompose into a medium salt + water + gas
Interact with alkalis to form an average salt + water

Question 18

Chemical properties of basic salts.

Answer 18

Thermally decompose into a metal oxide +gas/water
React with acids to form an average salt.
And dissociate completely like acid salts.

Question 19

Chemical properties of complex salts

Answer 19

Interaction with excess strong acid leads to formation of two medium salts and water
While the lack of a strong acid leads to the formation of an average salt of the active metal, amphoteric hydroxide and water
Interaction with a weak acid forms an acid salt with the active metal, an amphoteric hydroxide and water.
And interaction with CO2 or SO2 leads to an acid salt of the active metal +Amphoteric hydroxide.
When interacting with Fe3+, Al3+ or Cr3+, products are two amphoteric hydroxides, and active metal.