Advertisements
Advertisements
प्रश्न
A compound of lead has following percentage composition, Pb = 90.66%, O = 9.34%. Calculate empirical formula of a compound. [Pb = 207, O = 16]
Advertisements
उत्तर
Empirical formula of a compound:
| Element | Atomic mass |
Percentage | Relative number of | Simplest mole ratio | Whole number ratio |
| Pb | 207 | 90.66 | 90.66/207 = 0.44 | 0.44/0.44 = 1 | 1 x 3 = 3 |
| O | 16 | 9.34 | 9.34/16 = 0.58 | 0.58/0.44 = 1.32 | 1.32 x 3 = 3.96 = 4 |
Since the mole ratio for oxygen is fractional so we multiply the whole ratio by 3 to make i t a whole number.
So, the empirical formula of the compound is Pb3O4.
APPEARS IN
संबंधित प्रश्न
Consider the following reaction and based on the reaction answer the questions that follow:

Calculate:
1) the quantity in moles of (NH4)2Cr2O7 if 63gm of(NH4)2Cr2O7 is heated.
2) the quantity in moles of nitrogen formed.
3) the volume in liters or dm3 of N2 evolved at S.T.P.
4) the mass in grams of Cr2O3 formed at the same time
(Atomic masses: H=1, Cr= 52, N=14]
Ethane burns in oxygen to form CO2 and H2O according to the equation:
`2C_2H_6+7O_2 -> 4CO_2 + 6H_2O`
If 1250 cc of oxygen is burnt with 300 cc of ethane.
Calculate:
1) the volume of `CO_2` formed
2) the volume of unused `O_2`
Explain the terms empirical formula and molecular formula.
Give the empirical formula of: C6H12O6
Give the empirical formula of CH3COOH
A compound contains 87.5% by mass of nitrogen and 12.5% by mass of hydrogen. Determine the empirical formula of this compound.
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.
A compound 'X' consists of 4.8% of C and 95.2% of Br by mass.
Determine the empirical formula of this compound.
[C = 12, Br = 80]
Give the empirical formula of C6H18O3
A compound has the following percentage composition by mass: carbon 14.4%, hydrogen 1.2% and chlorine 84.5%. By what type of reaction could this compound be obtained from ethylene?
