Advertisements
Advertisements
प्रश्न
A gaseous hydrocarbon contains 82.76% of carbon. Given that its vapor density is 29, find its molecular formula. [C = 12, H = 11]
Advertisements
उत्तर
| Element | Percentage | Molecules | Simple ratio | Ration | Simple whole ratio |
| Carbon | 82.76 | `82.76/12` = 6.9 | `6.89/6.89` = 1 | `6.9/6.9` = 1 | 2 |
| Hydrogen | 17.24 | `17.24/1` = 17.24 | `17.24/6.89` = 2.5 | `17.24/6.9` = 2.5 | 5 |
Empirical formula = C2H5
Empirical formula mass = (12 × 2) + (1 × 5)
= 24 + 5
= 29
Vapour density = 29 ...(Given)
Molecular weight = 2 × Vapour density
Molecular weight = 2 × 29
= 58 gm
Molecular formula mass = n × Empirical formula mass
⇒ n = `"Molecular formula mass"/"Empirical formula mass"`
= `58/29`
= 2
Molecular formula = n × Empirical formula
= 2 × C2H5
= C4H10
संबंधित प्रश्न
Identify the term or substance based on the descriptions given below:
The property by virtue of which the compound has the same molecular formula but different structural formulae.
A compound made up of two elements X and Y has an empirical formula X2Y. If the atomic weight of X is 10 and that of Y is 5 and the compound ha a vapor density 25, find its molecular formula.
Explain the terms empirical formula and molecular formula.
Give the empirical formula of: C6H12O6
Give the empirical formula of C2H2
Give example of compound whose:
Empirical formula is the same as the molecular formula.
The empirical formula of a compound is C2H5. Its vapour density is 29. Determine the relative molecular mass of the compound and hence its molecular formula.
Calculate the percentage of water of crystallization in CuSO4. 5H2O
(H = 1, O = 16, S = 32, Cu = 64)
In a compound of magnesium (Mg = 24) and nitrogen (N = 14), 18 g of magnesium combines with 7g of nitrogen.
Deduce the simplest formula by answering the following questions:
- How many gram-atoms of magnesium are equal to 18g?
- How many gram-atoms of nitrogen are equal to 7g of nitrogen?
- Calculate the simple ratio of gram-atoms of magnesium to gram-atoms of nitrogen and hence the simplest formula of the compound formed.
Silicon (Si = 28) forms a compound with chlorine (Cl = 35.5) in which 5.6 g of silicon combines with 21.3 g of chlorine. Calculate the empirical formula of the compound.
