Draw the displayed formulae and name the structural isomers of ${\mathrm{C}}_3{\mathrm{H}}_7\mathrm{Cl}$.

When methylpropane is passed over a hot aluminium oxide catalyst, it can be converted into methylpropene. Methylpropene can be converted back into methylpropane by heating with hydrogen gas in the presence of a platinum / nickel catalyst:

$\underset{\mathrm{methylpropene}}{{\mathrm{H}}_2\mathrm{C}=\mathrm{C}\left({\mathrm{CH}}_3\right){\mathrm{CH}}_3}+{\mathrm{H}}_2\stackrel{\mathrm{Ni}/\mathrm{Pt} }{\to } \underset{\mathrm{methylpropane}}{{\mathrm{H}}_3\mathrm{C}-\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CH}}_3}$

What type of reaction best describes this reaction?

A chemist was investigating the best way to produce $1, 2$-dichloroethane. She reacted ethane with chlorine in the presence of UV light by the following reaction:

${\mathrm{C}}_2{\mathrm{H}}_{6 } \left(\mathrm{g}\right) +2{\mathrm{Cl}}_2 \left(\mathrm{g}\right) \to {\mathrm{C}}_2{\mathrm{H}}_4{\mathrm{CI}}_2 \left(\mathrm{l}\right)+2\mathrm{HCI} \left(\mathrm{g}\right)$

After doing this she found that $600 \mathrm{g}$ of ethane gave $148.5 \mathrm{g}$ of ${\mathrm{C}}_2{\mathrm{H}}_4{\mathrm{Cl}}_2$. Calculate how many moles of $1, 2$-dichloroethane are there in $148.5 \mathrm{g}$.