(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

1.046g of the hydrated chloride of a certain metal were dissolved in water and silver chloride was precipitated by the addition of a slight excess of silver nitrate solution. After purification the silver chloride had a mass of 1.231g. Calculate the percentage of chlorine in the hydrate. If it is of the form, MCl2.2H2O, calculate the relative atomic mass of the metal, M.

2. Relevant equations

My attempt at a balanced equation for this:

XCl.xH2O + H2O + AgNO3 ---> AgCl + XNO3

not sure if that's correct

3. The attempt at a solution

no. of mols AgCl produced = Mass/ Mr = 1.231/(108)+(35.5) = 8.58x 10^-3 mols AgCl

From the equation, I assumed a 1:1 ration between AgCl and the hydrated chloride.

Hence, no. of mols hydrated chloride = 8.58x10^-3.

I was trying to calculate the Mr of the hydrated chloride but how do i calculate this if i have 2 variables? The mass of the element X and the no. of mols of water?

I was thinking i'd need to calculate the Mr and then divide the mass of chlorine by the Mr of the compound...then multiply by 100 to find the %

Can someone please help me!

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# Homework Help: Gravimetric Analysis- precipitation method

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