posted by angela on .
A stock solution's hypochlorite activity was determined as follows: . -
2.00g of liquid sodium hypochlorite (NaOCl) was weighed into a flask and diluted with 50mL deionized water.10mL of 10% sulfuric acid and 10mL of 10% potasssium iodide were added, followed by titration with 0.1N sodium thiosulfate (Na2S2O3) until colorless.
% sodium hypochlorite
= (mL Na2S2O3)(0.1N)(0.03722)/2.00gNaOCl X 100
[The factor 0.03722 was derived by multiplying molecular weight of NaOCl (74.45g/mol) by 0.001 (mL to L conversion) and dividing by 2(mols of thiosulfate per hypochlorite).]
Please explain why we need to multiply by 0.1N? Thanks.
Break it down into steps.
Step 1 is to calculate #mew.
mL x N = number of milliequivalents.
Step 2 convert #mew to grams.
number of milliequivalents x milliequivalent weight = grams.
Step 3 converts grams to percent
(grams/weight sample) x 100 = percent.