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 relative molecular mass of Potassium chlorate.
(use K = 39, Cl = 35.5, O = 16, C = 12, H = 1, Na = 23, N = 14, S=32)
The usefulness of a fertilizer depends upon percentage of nitrogen present in it. Find which of the following is a better fertilizer:
(a) Ammonium nitrate [NH4NO3]
(b) Ammonium phosphate [(NH4)3PO4 (N=14,H=1,O=16,P=31)
Calculate the percentage of phosphorous in the fertilizer superphosphate, Ca(H2PO4)2. [Ca = 40, H =1, P =31, O = 16] (Correct to 1 decimal place)
A flask contains 3.2g of sulphur dioxide. Calculate the following: The number of molecules of sulphur dioxide present in the flask.
A compound 'X' consists of 4.8% of C and 95.2% of Br by mass.
If the vapour density of the compound is 252, what is the molecular formula of the compound?
The equation for the burning of octane is:
\[\ce{2C6H18 + 25O2 -> 16CO2 + 18H2O}\]
If the relative molecular mass of carbon dioxide is 44, what is the mass of carbon dioxide produced by burning two moles of octane?
Give one word or phrase for the following:
Formation of ions from molecules.
Calculate the relative molecular mass of:
(NH4)2 Cr2O7
Find the weight of 0.5 mole of O2.
