Question

What is the molecular formula of C3H2N with 260.24g/mol

Answer 1

C3H2N tells you the lowest possible whole number ratio of atoms in that molecule. That empirical formula must have the same ratio as the actual, molecular formula.
 

The empirical mass and molecular mass must share the same ratio as the formulas do, so find the mass of C3H2N: 3(12g)+2(1g)+14g=52g

Compare that to the molecular weight of 260g.

MFEF=MWEWsoMFEF=260g52g=5the actual formula is five times heavier than the empirical formula, so take the empirical formula and multiply each subscript by 5. 

Answer 2

Answer:

The molecular formula of the compound is  $C_{15}H_{10}N_5$.

Explanation:

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{molecular mass}}{\text{empirical mass}}$

Molecular mass of the compound = 260.24 g/mol

Empirical mass of the compound :

$C_3H_2N=3\imes 12 g/mol+3\times 1 g/mol+14 g/mol =52 g/mol$

To calculate the valency is :

$n=\frac{260.24 g/mol}{52 g/mol}=5$

The molecular formula of the compound:

=$C_{3\times 5}H_{2\times 5}N_{1\times 5}=C_{15}H_{10}N_5$