Question

A compound of C,H and N contains 66.70 of C 7.41% of H, 25.90% of N ,,the molecular mass of compound was found to be 108...find its empirical formula and molecular formula

Answer 1

Question is almost done but just Vapor Density of the compound is required. Without it, the data is insufficient.

Answer 2

First assume an original sample of 100 grams-
\[66.70/100=.667g\]
\[7.41/100=.0741g\]
\[25.90/100= .259g\]
Now convert grams to moles
\[.667/12.01=.0555mol\]
\[.0741/1.008=.0735mol\]
\[.259/14.01=.0185mol\]
Now divide each by the smallest amount
\[.0555/.0185=3\]
\[.0735/.0185=4\]
\[.0185/.0185=1\]
Use these numbers as the formula numbers for the empirical formula-
\[C _{3}H _{4}N\]
Now calculate the molar mass of this molecule
54.07g
And divide the experimental mass by this one-
\[108/54.07=2\]
Now multiply each of the empirical formula units by this number-
\[C _{6}H _{8}N _{2}\]
And that's it.