A chemist wants to extract the gold from 15.0g of gold(II) chloride dihydrate, AuCl3 x 2H20, What mass of gold could be obtained from this sample?

Question

Also how would you find the molar mass of of 2H20 with the coefficient 2 in front?

Answer 1

http://www.jiskha.com/display.cgi?id=1302059899
The coefficient of 2 means to multiply by 2; the molar mass of H2O is 18, the molar mass of 2H2O is 36.