When reacted with a small quantity of water, SiCl4 produces an oxychloride X, SixClyOz. The mass spectrum of X shows peaks at mass numbers of 133, 149, 247, 263 and 396. (You should assume that the species responsible for all these peaks contain the 16O, the 35Cl and the 28Si isotopes only.) (i) Use these data to deduce the molecular formula of X This is from j10,p42, Q3d. http://www.xtremepapers.com/CIE/Interna ... _qp_42.pdf It would be tedious to find it one by one just to reach the value 396. Is there any simple method to solve this question?