A scientist uses 3 g of water (H2O) in an experiment. Which option describes the first step in calculating the number of molecules in 3 g of water?

A. apply avogardro's number, 6.022 x 10^23
B. determine the molar mass of water
C. identify the molar masses of H and O
D. calculate the number of moles of water

1 answer

B. determine the molar mass of water