I am attempting to determine a good sample size for unknown titrations, I am giv

Question

I am attempting to determine a good sample size for unknown titrations, I am given a few guidelines as to how to calculate a reasonable mass, but I am completely lost as to how to go about doing that. Any help would be much appreciated! (with steps please!!) Thank you! Here is the given "guideline" information:

Assume your NaOH solution is 0.050 M

Assume the sample is 55% KHP

Assume the volume of NaOH required is 35 mL

"Now calculate the sample size of the unknown KHP that would be consistent with these assumptions"

Explanation / Answer

KHP and NaOH reacts in 1:1 ratio

hence at end point of titration NaOH moles used = KHP moles

NaOH moles = Mx V ( in Liters) = ( 0.05 x 35/1000) = 0.00175

KHP moles = 0.00175

KHP mass = moles x molar mass of KHP = 0.00175 x 204.22 = 0.3574 g

Sample is 55 % KHP which means 55 g KHP per 100 g sample

hence mass of sample required = ( 0.3574) x ( 100 /55) = 0.65 grams

Thus we need 0.65 grams sample of 55% KHP

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