A sugar crystal contains approximately 1.2×10^17 sucrose molecules. what is its mass in mg?

 A sugar crystal contains approximately 1.2×1017 sucrose ({\rm{C}}_{12} {\rm{H}}_{22} {\rm{O}}_{11}) molecules. What is its mass in mg?

Find molar mass of sucrose - from memory it's about 342g and will contain 6.02 x 10^23 molecules. So convert mass to mg and then find the mass of 1.2 x 10^17 molecules