October 17, 2019, 02:14:42 PM
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Topic: Determining the number of moles/percent by mass of MgCl2 in mixture  (Read 138 times)

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Offline Baksu888

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This is one of the questions on my AP Chemistry Quiz that my teacher asked me to revise on my own, but the problem is, I have no idea where to even begin with this problem. If you guys can give me a resource or help me out with some pointers that would be great!

Here's the problem:

In the second experiment, a student is given 2.94g of a mixture containing anhydrous MgCl2 and KNO3. To determine the percentage by mass of MgCl2 in the mixture, the student uses excess AgNO3(aq) to precipitate the chloride ion as AgCl(s). This means the MgCl2 reacts with the AgNO3 to create a solid AgCl. The student determines the mass of the formed AgCl precipitate to be 5.48g. On the basis of this information, calculate:

1.) The number of moles of MgCl2 in the original mixture.
2.) The percent by mass of MgCl2 in the original mixture.

Offline Borek

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Re: Determining the number of moles/percent by mass of MgCl2 in mixture
« Reply #1 on: October 12, 2019, 04:02:18 AM »
Start with the reaction equation and follow the stoichiometry.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

Offline Baksu888

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Re: Determining the number of moles/percent by mass of MgCl2 in mixture
« Reply #2 on: October 12, 2019, 05:23:08 PM »
https://imgur.com/QUA6RRf

Can you check my work?
« Last Edit: October 12, 2019, 06:01:40 PM by Borek »

Offline Borek

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Re: Determining the number of moles/percent by mass of MgCl2 in mixture
« Reply #3 on: October 12, 2019, 06:03:50 PM »
Wasn't that hard.
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