A compound contains 'N' and 'O' atom. The ratio of mass percentage of 'N' and 'O' is 7:16. If the vapour density of compound is 46, then find the no of 'O' atoms present per molecule of the compound.
%N/%O = 7/16 but 7/16 is the same as 14/32 and that means the empirical formula is NO2.
vapor density = 46 = mm gas/mm H2 = mmgas/2 so mm gas = 92 (where mm = molar mass)
empirical formula x some # = molecular formula = 96 so the unit # must be 2.
(NO2)2 or N2O4 must be the molecular formula.
To find the number of 'O' atoms per molecule of the compound, we need to use the concept of the empirical formula and molar mass.
1. First, let's assume the compound contains 'x' number of nitrogen (N) atoms and 'y' number of oxygen (O) atoms per molecule.
2. The ratio of the mass percentage of 'N' to 'O' is given as 7:16. This means that for every 7 parts of nitrogen, there are 16 parts of oxygen.
Therefore, the mass ratio of nitrogen to oxygen can be written as:
(Mass of Nitrogen)/(Mass of Oxygen) = 7/16
3. The compound's vapor density is given as 46. Vapor density represents the ratio of the molecular mass of a gas to that of hydrogen gas (H2).
The molecular weight of compound = 46 * 2 (because vapor density of compound = 46, and hydrogen's atomic mass is 2 grams/mole)
4. The molecular mass of the compound can be expressed as:
(Mass of Nitrogen * Atomic mass of Nitrogen) + (Mass of Oxygen * Atomic mass of Oxygen) = Total Molecular Mass of Compound
Let's use variables to represent the atomic masses of nitrogen (N) and oxygen (O). Therefore:
(7x * atomic mass of N) + (16y * atomic mass of O) = 46 * 2
5. To solve for 'x' and 'y,' we need additional information.
- One approach is to divide both sides of the equation by one of the atomic masses (e.g., atomic mass of N) and set it equal to the ratio of 'x' to 'y'.
- Another approach is to assume 'x' or 'y' (typically the smaller value) to find the values of 'x' and 'y' that satisfy the equation.
Unfortunately, without further information or assumptions, we cannot determine the number of oxygen atoms (O) present per molecule of the compound.