Question

The mean sea water concentration of DMS in the ocean is 2.7 nm (nanomolar). How many molecules of DMS are present in 1.0 $m^3$of sea water?

• A. 16.254 x 10${}^{17}$ molecules
• B. 2.7 x 10${}^{17}$ molecules
• C. 2.7 x 10${}^{-6}$ molecules
• D. 16.257 x 10${}^9$ molecules

Answer 1

The correct option is A 16.254 x 10${}^{17}$ molecules

$1m^3=1000litres$,

$2.7nm$ implies that 1 litre has $2.7nm$, molecules in 1 mole $=6.023\times {10}^{23}$

molecules in 1000 litres of sea water $=2.7\times {10}^{-9}\times 6.023\times {10}^{23}\times 1000=16.254\times {10}^{17}molecules$.