Chloral hydrate, molecular formula

Chloral hydrate ( knockout drops ) is found to have the molecular formula C2H3CI3O2. 

The compound chloral hydrate, known in detective stories as knockout drops, is composed of 14.52% C, 1.83% H, 64.30% Cl, and 19.35% O by mass and has a molar mass of 165.4 g/mol. (a) What is the empirical formula of this substance (b) What is the molecular formula of this substance (c) Draw the Lewis structure of the molecule, assuming that the Cl atoms bond to a single C atom and that there are a C—C bond and two C—O bonds in the compound. 

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