The Student Room Group

Acids and bases

This question is about vitamin C, C6H8O6.
Vitamin C is a weak monobasic acid with a Ka value of 6.76 × 10–5 mol dm–3.

ii) A bottle of vitamin C supplements contains tablets, each containing 500 mg of vitamin C.
A student dissolves three vitamin C tablets in water and makes up the solution to a volume of 250.0cm3.
Calculate the pH of the solution.
Give your answer to two decimal places.

—- I get how to do most of it except in the first part the markscheme multiplied by 3 to find moles of vitamin c which i dont get
That will be because there are three tablets, I assume. 500mg x 3 divided by the Mr of vitamin C will give you the total amount of moles present.

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