why is this D not C ? A level Chemistry Watch

Leah.J
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I don't think D is wrong, I just don't hink C is wrong either.
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Pigster
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(Original post by Leah.J)
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I don't think D is wrong, I just don't hink C is wrong either.
SHE requires [H+] of 1 mol dm-3.

1 mol dm-3 of H2SO4 has [H+] or 2 mol dm-3.
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Leah.J
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(Original post by Pigster)
SHE requires [H+] of 1 mol dm-3.

1 mol dm-3 of H2SO4 has [H+] or 2 mol dm-3.
But They didn't say the conc. of the acid used had to be 1 mol dm3

We can use 0.5 mol dm-3 of H2SO4

The question asked for a 1 mol dm-3 H+ concentration
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Meowstic
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H2SO4 is a strong acid (pKa -9) but HSO4- is a much weaker acid (pKa 2, closer to ethanoic acid with something like 4.8 but that's from memory), the concentration of H+ will be too prone to conditions for use as a standard because the second proton is less readily removed. The standard hydrogen electrode is specifically hydrochloric acid.
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