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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: caitcait on September 18, 2011, 02:17:50 PM

Title: Unknown element in quantitative conversion
Post by: caitcait on September 18, 2011, 02:17:50 PM

An element X forms an iodide (XI₃) and a chloride (XCl₃). The iodide is quantitatively converted to the chloride when it is heated in a stream of chlorine: 2XI₃+3Cl₂ :rarrow: 2XCl₃+ 3I₂   If 0.6000g  of XI₃   is treated, 0.2832g  of XCl₃ is obtained.  Calculate the atomic weight of the element X and identify the element.

Title: Re: Unknown element in quantitative conversion
Post by: caitcait on September 18, 2011, 06:22:25 PM

I dont even know where to start with this, I tried converting everything to moles, but I don't think there is enough information?

Title: Re: Unknown element in quantitative conversion
Post by: Borek on September 18, 2011, 06:42:42 PM

There is enough information. Mass change depends on the number of moles of the substance. If there is 1 mole of XI₃, you have three moles of I replaced with Cl - can you calculate mass change for 1 mole? You know mass change of the sample - can you use ratios to calculate number of moles of the substance?