Advertisements
Advertisements
प्रश्न
A gaseous hydrocarbon contains 82.76% of carbon. Given that its vapour density is 29, find its molecular formula.
[C = 12, H = 1]
Advertisements
उत्तर
% of carbon = 82.76%
% of hydrogen = 100 - 82.76 = 17.24%
| Element | % weight | Atomic weight | Relative No. of moles | Simplest Ratio |
| C | 82.76 | 12 | 82.76/12 = 6.89 | 6.89/6.8 = 1 x 2 = 2 |
| H | 17.24 | 1 | 17.24/1 = 17.24 | 17.24/6.89 =2.5 x 2 = 5 |
Empirical formula = C2H5
Empirical formula weight = 2 × 12 + 1 × 5 = 24 + 5 = 29
Vapour density = 29
Relative molecular mass = 29 × 2 = 58
N = `"Relative molecular mass"/"Empirical weight"`
= `58/29` = 2
Molecular formula = n x empirical formula
= 2 x C2H5
= C4H10
APPEARS IN
संबंधित प्रश्न
Give balanced chemical equations for the following conversions A, B, and C:
Calculate the percentage composition of oxygen in lead nitrate [Pb(NO3)2]. [Pb = 207, N= 14, O = 16]
Potassium nitrate on strong heating decomposes as under :
2KNO3 → 2KNO2 + O2
Calculate : Weight of potassium nitrite formed.
(K = 39, 0 = 16, N = 14)
What weight of sulphuric acid will be required to dissolve 3g of magnesium carbonate?
[Mg = 24, C =12, 0 = 16 ]
MgCO3 + H2SO4 → MgSO4 + H2O+ CO2
Calculate the percentage of boron (B) in borax (Na2B4O7.10H2O). [H = 1, B = 11, O = 16, Na = 23],
answer correct to 1 decimal place.
Chlorine, nitrogen, ammonia and sulphur dioxide gases are collected under the same conditions of temperature and pressure.
Copy the following table which gives the volumes of the gases collected, and the number of molecules (X) in 20L of nitrogen.You are to complete the table by giving the number of molecules in th e other gases, in terms of X.
| Gas | Volume(litres) | Number of molecules |
| Chlorine | 10 | |
| Nitrogen | 20 | X |
| Ammonia | 20 | |
| Sulphur dioxide | 5 |
The reaction of potassium permanganate (VII) with acidified iron (II) sulphate is given below:
2KMno4 + 10FeSO4 + 8H2O → K2SO4 + 2MnSO4 + 5Fe2(SO4)3 + 8H2O
If 15.8g of potassium permanganate (VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction.
A certain gas 'X' occupies a volume of 100 cm3 at S.T.P. and weighs 0.5 g. Find its relative molecular mass.
Which of the following contains maximum number of molecules?
The following question refers to one mole of chlorine gas.
If the relative atomic mass of chlorine is 35.5, what will be the mass of 1 mole of chlorine gas?
