(Solved): 8. Determine the number of CH2Cl2 molecules in 42.463g of CH2Cl2. The molar mass ...

8. Determine the number of ${\mathrm{CH}}_2{\mathrm{Cl}}_2$ molecules in $42.463\mathrm{g}$ of ${\mathrm{CH}}_2{\mathrm{Cl}}_2$. The molar mass of ${\mathrm{CH}}_2{\mathrm{Cl}}_2$ is $84.926\mathrm{g}/\mathrm{mol}$. a) $0.29412\times 10^{21}$ molecules b) $1.7742\times 10^{23}$ molecules c) $1.2044\times 10^{27}$ molecules d) $1.5121\times 10^{25}$ molecules e) $3.0110\times 10^{23}$ molecules 9. The empirical formula an organic compound is ${\mathrm{C}}_3{\mathrm{H}}_2\mathrm{N}$, and its molar mass is $312.29\mathrm{g}/\mathrm{mol}$. What is its molecular formula? a) ${\mathrm{C}}_3{\mathrm{H}}_2\mathrm{N}$ b) ${\mathrm{C}}_9{\mathrm{H}}_6{\mathrm{N}}_3$ c) ${\mathrm{C}}_6{\mathrm{H}}_4{\mathrm{N}}_2$ d) ${\mathrm{C}}_{12}{\mathrm{H}}_8{\mathrm{N}}_4$ e) ${\mathrm{C}}_{18}{\mathrm{H}}_{12}{\mathrm{N}}_6$