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प्रश्न
Define ‘formula mass’ of a compound.
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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
Calculate the number of aluminium ions present in 0.051 g of aluminium oxide.
(Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27 u)
Write the names of `"ZnCl"_2 ` compounds :
State whether the following statements are true or false :
A chloride ion has negative charge because it has more electrons than a neutral atom.
Fill in the following blank with suitable word:
A sulphide ion has negative 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
Write the basic radicals and acidic radicals of the following and then write the chemical formulae of these compound.
Calcium silicate
Write the basic radicals and acidic radicals of the following and then write the chemical formulae of these compound.
Magnesium phosphate
Write the basic radicals and acidic radicals of the following and then write the chemical formulae of these compound.
Stannic phosphate
Complete the following table.
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Acid Radicals `→` |
Chloride |
Nitrate |
Sulphate |
Carbonate |
Hydroxide |
Phosphate |
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Basic Radicals `↓` |
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Magnesium |
MgCl2 |
Mg(NO3)2 |
MgSO4 |
MgCO3 |
Mg(OH)2 |
Mg3(PO4)2 |
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Sodium |
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Zinc |
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Silver |
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Ammonium |
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Calcium |
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Iron (II) |
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Potassium |
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State if the following element or radical is divalent?
Dichromate
