an organic compound contains 49.3 percent carbon,6.84percent hydrogen and its vapour density is 73.molecular formula of compound
Take a 100 g sample. That gives you
49.3 g C
6.84 g H
You need to know what the remainder is. I suspect oxygen, then
43.86 g oxygen.
Convert to moles.
49.3/12 = ??
6.84/1 = ??
43.86/16 = ??
Now find the ratio of the atoms to each other with the smallest whole number being 1. The easy way to do that is to divide the smallest number by itself; then divide the other numbers by the same small number. Then round to whole numbers; however, don't found too much. That is, if close to 1/2, then multiply all of the number by 2 to arrive at whole numbers. Post your work if you get stuck.
To determine the molecular formula of an organic compound, we need to first calculate the empirical formula and then determine the multiple of it to get the molecular formula.
1. Start by assuming we have 100 grams of the compound.
2. Calculate the number of moles of each element in the compound:
- Carbon: 49.3 grams ÷ atomic mass of carbon (12.01 g/mol)
- Hydrogen: 6.84 grams ÷ atomic mass of hydrogen (1.008 g/mol)
3. Next, divide the moles of each element by the smallest number of moles obtained in step 2. This will give us the empirical formula ratio.
- Divide the moles of carbon and hydrogen by the smallest number of moles obtained.
4. Simplify the ratio if necessary by dividing all the values by the smallest value.
5. Now, determine the empirical formula by using the ratios obtained and the element symbols:
- Multiply each element's symbol by the number obtained in step 4 to get the empirical formula.
6. Finally, to find the molecular formula, we need to calculate the molecular mass of the empirical formula. This can be done by adding up the atomic masses of each element in the empirical formula.
7. Divide the molar mass of the empirical formula by the vapor density to find the empirical formula mass.
8. The molecular formula will then be a multiple of the empirical formula if the empirical formula mass is an integer multiple of the vapor density.
By following this process, you can calculate the molecular formula of the compound.