Question

Benzene reacts with hot concentrated nitric acid dissolved in sulfuric acid to give chiefly nitrobenzene, C6H5NO2. A by-product is often obtained, which consists of 42.86% C, 2.40% H, and 16.67% N (by mass). The boiling point of a solution of 5.5 g of the by-product in 45 g of benzene was 1.84°C higher than that of benzene.

Answer 1

I don't see a question here.

Answer 2

What is the molar mass of the by-product?
Calculate the molecular formula of the by-product.
Calculate the empirical formula of the by-product.

Answer 3

So would the molar mass be 168.2?
Empirical be c3h2n1o2?

Answer 4

Yes, empirical formula is C3H2N10.
Empirical formula mass is 178. (3*12) + (2*1) + (10*14) = 178
The approximate molar mass is given by the boiling point elevation.

delta T = Kb*m
1.84 = 2.53*m
m = about 0.7 but you need to go through this and all other calculations. I've estimated here and there.
m = mols/kg solvent
0.7 = mols/0.045 and mols = about 0.03
Then mols = g/molar mass or molar mass = g/mol = 5.5/0.0327 = about 168 for the molar mass approximately.
168/178 = about 0.94 and round that to 1 so the molar mass is 178 which is the same as the empirical mass..

Answer 5

HOW DO I FIGURE OUT THE MOLECULAR FORMULA FROM THE DATA?

Answer 6

Since the empirical formula mass is about the same as the molecular formula mass then the molecular formula is the same as the empirical formula.