How do you calculate the number of moles of bromine present in 16.0ml of Br2 whose density is 3.12gml?

Answer 1

First convert the volume of the Br2 into grams by using:

D=M/V
So we are given that volume=16.0 ml and density=3.12g/ml.

M=D*V
M=(3.12g/ml)*(16.0ml)=49.92 g

Then we use #moles of a substance=#grams present/Formula weight(# of grams of Br2 in 1 mol of Br2)

The Formula weight(molar mass) of Br2=2*(79.9 g/mol)=159.80 g/mol Br2

#moles of Br2=49.92g/159.80g/mol Br2=

.312 moles of Br2 present.