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प्रश्न
Define ‘formula mass’ of a compound.
उत्तर
Formula mass of a compound is the relative mass of its 'formula unit' compared to the mass of a carbon-12 atom (which has a mass of exactly 12 units).
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संबंधित प्रश्न
Name the following radicals :
HC03
The valency of calcium is 2. Write the valencies of other radical in the following :
- CaO
- Ca(OH)2
- CaC03
- CaCl2
Tick (√) the correct answer.
The sulphate radical is written as S042-. What is the formula of calcium sulphate ?
State whether the following statements are true or false:
A sodium ion has positive charge because it has more protons than a neutral atom.
Name the particle which has 18 electrons, 18 neutrons and 17 protons in it.
Fill in the following blank with suitable word:
A potassium ion has positive charge because it contains less............... than.....................
The valencies (or charges) of some of the ions are given below :
| Ion | Valency (Charge) | Ion | Valency (Charge) |
| Sodium ion | 1+ | Bromide ion | 1– |
| Ammonium ion | 1+ | Hydroxide ion | 1– |
| Calcium ion | 2+ | Sulphate ion | 2– |
| Lead ion | 2+ | Phosphate ion | 3– |
Using this information, write down the formulae of the following compounds :
(i) Sodium phosphate
(ii) Ammonium sulphate
(iii) Calcium hydroxide
(iv) Lead bromide
Give example.
Trivalent basic radicals
Write the basic radicals and acidic radicals of the following and then write the chemical formulae of these compound.
Chromium sulphate
Write the basic radicals and acidic radicals of the following and then write the chemical formulae of these compound.
Stannic phosphate
