Multiple part question... please help. So confused in Chemistry!!! Sorry it is s

Question

Multiple part question... please help. So confused in Chemistry!!!

Sorry it is so long, I have tried for so long cannot get the right answers. Thank you so much.

After digesting the vitamin tablet using 6 M HCI, you will filter the digest into a 100 mL volumetric flask, and fill to volume with RO water. After filling to volume with RO water, you will dilute the resulting solution two times. Before filling the second dilution flask with RO water, you will add reagents: Number Units R-hat volume ofhydroxylamine nydrochloride will you add? mL O O O the congo red paper turns red the solution turns orange the solution has a pH of 7 Then you will add 2 M sodium acetate until After the sodium acetate you will add orthophenanthroline. What volume and concentration will you add? Number Units Number g/L o-phen Incorrect.

Explanation / Answer

1) Determination of quantity of iron in vitamin tablet colorimetrically

    For 50 ml test solution add

        5 mL of 2%(v/v) hydroxylamine hydrochloride solution

        10 mL of 10%(w/v) sodium acetate solution

        25 mL of 1% 1,10-phenanthroline solution

        And fill to the mark with water

Depends on the volume of iron solution to be prepared,if 100 ml solution, the volume is to be doubled.

Sodium acetate to be added until the color changes to red.pH is managed between 6 and 9.

2)mass of FAS=0.1518g

Moles of FAS=0.1518g/392.14g/mol=3.87*10^-4 moles

(NH4)2Fe(SO4)2.H2O=or FAS one mole has one mole Fe

So 3.87*10^-4 moles of FAS has 3.87*10^-4 moles of Fe

Mass of Fe in FAS=3.87*10^-4 moles * 55.85g/mol=0.0216g

So concentration of Fe(w/V)=0.0216g/250 ml *1000ml/L=0.0864 g/L

% w/v=86.4mg/L =86.4 ppm(answer)

3)Fe conc=150.00ppm =150 mg/L

For 525 ml mass of Fe required=150 mg/L* 0.525 L=78.75 mg=0.07875 g

Moles of Fe=0.07875g/55.85 g/mol=0.00141 moles

So moles of FAS=0.00141 moles (since FAS one mole has one mole Fe)

Mass of FAS required=0.00141 moles*392.14 g/mol=0.553 g (answer)

4)y=0.240x+0.005

Y=absorbance=0.466

0.466=0.240x+0.005

0.466-0.005=0.240x

X=(0.466-0.005)/0.240=1.921 ppm (answer)

more information needed about the experiment to answer the rest.

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