ICSE Class 9 Answered
How to find valency of compounds like 2 for SO4, 1 for NO3 and so on. Explain with the help of more examples. (Please explain using the simplest way at basic level but it should be correct)
Thank You.
Asked by tdeshpande502 | 19 Jun, 2020, 01:23: PM
Expert Answer
In case of group of atoms you have to remember the chemical formula.
Following are some tables including chemical formula and valency.
Representation of some positive radicals and their valency
Name of Radical
Representation
Valency
Hydrogen
H+
1
Sodium
Na+
1
Potassium
K+
1
Silver
Ag+
1
Ammonium
NH4+
2
Magnesium
Mg2+
2
Calcium
Ca2+
2
Iron(II)
Fe2+
2
Gold
Au2+
2
Copper(II)
Cu2+
2
Iron(III)
Fe3+
3
Aluminium
Al3+
3
5Platinum(IV)
Pt4+
4
Representation of some negative radicals and their valency
Name of Radical
Representation
Valency
Chloride
Cl−
1
Bromide
Br−
1
Hydroxide
OH−
1
Acetate
CH3COO−
1
Nitrate
NO3−
1
Nitrite
NO2−
1
Bisulphate
HSO4−
1
Bisulphite
HSO3−
1
Bicarbonate
HCO3−
1
Oxide
O2−
2
Carbonate
CO32−
2
Sulphate
SO42−
2
Sulphite
SO32−
2
Dichromate
Cr2O72−
2
Nitrite
N3−
3
Phosphate
PO43−
3
Step-by-step method for writing a chemical formula:
Representation of some positive radicals and their valency
|
Name of Radical |
Representation |
Valency |
|
Hydrogen |
H+ |
1 |
|
Sodium |
Na+ |
1 |
|
Potassium |
K+ |
1 |
|
Silver |
Ag+ |
1 |
|
Ammonium |
NH4+ |
2 |
|
Magnesium |
Mg2+ |
2 |
|
Calcium |
Ca2+ |
2 |
|
Iron(II) |
Fe2+ |
2 |
|
Gold |
Au2+ |
2 |
|
Copper(II) |
Cu2+ |
2 |
|
Iron(III) |
Fe3+ |
3 |
|
Aluminium |
Al3+ |
3 |
|
5Platinum(IV) |
Pt4+ |
4 |
Representation of some negative radicals and their valency
|
Name of Radical |
Representation |
Valency |
|
Chloride |
Cl− |
1 |
|
Bromide |
Br− |
1 |
|
Hydroxide |
OH− |
1 |
|
Acetate |
CH3COO− |
1 |
|
Nitrate |
NO3− |
1 |
|
Nitrite |
NO2− |
1 |
|
Bisulphate |
HSO4− |
1 |
|
Bisulphite |
HSO3− |
1 |
|
Bicarbonate |
HCO3− |
1 |
|
Oxide |
O2− |
2 |
|
Carbonate |
CO32− |
2 |
|
Sulphate |
SO42− |
2 |
|
Sulphite |
SO32− |
2 |
|
Dichromate |
Cr2O72− |
2 |
|
Nitrite |
N3− |
3 |
|
Phosphate |
PO43− |
3 |
Step-by-step method for writing a chemical formula:
Answered by Ramandeep | 19 Jun, 2020, 01:40: PM
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