Calculation error help!

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Tara 1F
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Joined: Fri Jun 23, 2017 11:39 am

Calculation error help!

Postby Tara 1F » Mon Jul 03, 2017 4:15 pm

A solution is prepared by dissolving 55.1g of KCl in approx 75mL water and then adding water to a final volume of 125mL. What is the molarity of Kcl (aq) in this solution?

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Re: Calculation error help!

Postby Chem_Mod » Wed Jul 05, 2017 10:28 am

The 75 mL is not important; it determines an intermediate concentration. Convert the grams of KCl to moles and divide by the final volume.

Yixiao Hu 3C
Posts: 45
Joined: Fri Sep 28, 2018 12:19 am

Re: Calculation error help!

Postby Yixiao Hu 3C » Sun Oct 07, 2018 11:22 pm

you should use the formula n=m/M for the moles of kcl; and then you should use the formula molarity=n/v . the first 75ml here is just useless. you only need the final volume.

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