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# titration question help watch

1. here's the question. it has 3 parts and part B is the one i'm stuck on currently.

the answer which I get is 5.8 as the Mr however there is no metal with that Mr, or even close to is Lithium.

Is it right? Thanks.
2. hey, i got the Mr as 23.3 which is pretty close to sodium
3. Ok lets go:

12.03cm3 -> 0.01205dm3

0.01205 x 12.05 = 241/160000 : This is the mol of HCl used. Looking at the equation, the ratio of HCl : MOH is 1:1. Therefore, the mols of MOH titrated was 241/160000

Since a portion of 10cm3 of the solution had 241/160000 mols of MOH, 100cm3 of the solution would have 241/16000 mols.

Since the ratio of M2O : MOH is 1:2, you can work out the mols of M2O is half of the mols of MOH. Therefore, mols of M2O used is 241/32000

Since the ratio of M : M2O is 4:2 (which can be simplified to 2:1), you can work out the mols of M used is double the mols of M2O. Therefore, mols of M used is 241/16000

Doing 0.35/(241/16000) = 23.24 which is pretty close to sodium.

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Updated: March 1, 2018
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