How much energy does an electric hair dryer use if it draws 8.3 amps of current when using 120 volts for 5.0 minutes?

Iknow #2 is d. i just need to know why

Can someone me with these questions plz.

Scientists are often interested in knowing the molar heat of combustion – the heat released during the combustion of one mole of a substance. use the periodic table to find molar masses. how many moles of ethanol are present in the sample?