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प्रश्न
A metal M, forms a volatile chloride containing 65.5% Chlorine. If the density of the chloride relative to hydrogen is 162.5, find the molecular formula of the chloride. [M = 56, Cl = 35.5]
उत्तर
Given, density of chloride relative to hydrogen = 162.5
Percentage of chlorine = 65.5‰
Percentage of Metal M = 100 - 65.5 = 34.5‰
| Element | Atomic mass | Percentage | Relative number of moles | Simplest mole ratio | Whole number ratio |
| M | 56 | 34.5 | 34.5/56 = 0.62 | 0.62/0.62 = 1 | 1 |
| Cl | 35.5 | 65.5 | 65.5/35.5 =1.85 | 1.85/0.62 = 2.98 | 3 |
Empirical formula = MCl3
Empirical formula mass = 56 + 3 x 35.5 = 162.5
Molecular mass = 2 x Vapour density = 2 x 162.5 = 325
n = Molecular mass / Empirical formula mass
= 325/162.5 = 2
Molecular formula = n x empirical formula
= 2 X MCl3 = M2Cl6
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