Question

Determine the molecular formulas to which the following empirical formulas and molar massespertain
a. SNH (188.35 g/mol)
b. NPCI₂ (347.64 g/mol)
C. COC₄O₄ (341.94 g/mol)
d. SN (184.32 g/mol)

Short answer

The molecular formula from empirical formula and molar mass can be found.

Step-by-step solution

Molecular formula for SNH

The empirical formula of SNH can be $32.065+14.006+1.0079=47.0789\raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol}$}\right.$

$\begin{array}{rcl}\frac{\mathrm{Molar}\mathrm{Mass}}{\mathrm{Empirical}\mathrm{formula}\mathrm{mass}}& =& \frac{188.35}{47.0789}\\ & =& {\mathrm{S}}_4{\mathrm{N}}_4{\mathrm{H}}_4\end{array}$

Molecular formula for NPCI2

The empirical formula of NPCI₂ can be

$14.006+30.973=115.885\raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol}$}\right.$

$\begin{array}{rcl}\frac{\mathrm{Molar}\mathrm{mass}}{\mathrm{Empirical}\mathrm{formula}\mathrm{mass}}& =& \frac{347.64}{115.885}\\ & =& {\mathrm{N}}_3{\mathrm{P}}_3{\mathrm{Cl}}_6\end{array}$

Molecular formula for COC4O4

The empirical formula of COC₄O₄ can be

$58.933+48.0404=170.96\raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol}$}\right.$

$\begin{array}{rcl}\frac{\mathrm{Molar}\mathrm{mass}}{\mathrm{Empirical}\mathrm{formula}\mathrm{mass}}& =& \frac{341.94}{170.96}\\ & =& {\mathrm{Co}}_2{\mathrm{C}}_8{\mathrm{O}}_8\end{array}$

Molecular formula for SN

The empirical formula of SN can be

$32.065+14.006=46.071\raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol}$}\right.$

$\begin{array}{rcl}\frac{\mathrm{Molar}\mathrm{Mass}}{\mathrm{Empirical}\mathrm{formula}\mathrm{mass}}& =& \frac{184.32}{46.071}\\ & =& {\mathrm{S}}_4{\mathrm{N}}_4\end{array}$