f325 exam tommorow and im stuck on a a past paper question

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nmjasdk
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#1
Report Thread starter 7 years ago
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http://www.ocr.org.uk/Images/79734-q...d-elements.pdf

and the mark scheme

http://www.ocr.org.uk/Images/64622-m...ts-january.pdf

so this is the paper on q4 d ii i dont get how they used the values they did to calculate the Ka.
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Pigster
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Ka = [H+] x [A-]/[HA]

In this case A- = HCO3- and HA = H2CO3

[A-] = 10.5 and [HA] = 1 (the given ratio)
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