Unsaturated hydrocarbons contain multiple bonds between the two $\mathrm{C}$-atoms and show addition reactions. Give the test to distinguish ethane from ethene.

Give the chemical formula and structural formula of:

Benzene 

Give the chemical formula and structural formula of:  

Propanoic acid

Give the chemical formula and structural formula of:

Propanal

Give the chemical formula and structural formula of:  

Ethanol

Give the chemical formula and structural formula of:

Cyclopropane

Give the name of the following organic compounds:

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}$

Give the name of the following organic compounds: 

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{C}\equiv \mathrm{CH}$

Give the name of the following organic compounds: 

${\mathrm{CH}}_3\mathrm{Cl}$