Question

How much mg of iron are there in 100g of spinach.
if we burned 5.20g of spinach and added 10 ml of 2.0 M HCl into the spinach ashes.Then filtered the ashes and used 5 ml of that solution to put it in a testube and added 5 ml of 1.5 M KSCN in the testube. We then use a spectrometer to determine its absorbance, which is 0.353. How do I solve this

Answer 1

The parameter found was a=4.43236 Lmmol−1=4.43236 mM−1a=4.43236 Lmmol−1=4.43236 mM−1.

Calculate the Concentration of Fe Ions Present

You have measured an absorbance of 0.015 with a corresponding concentration of cmeas=3.38⋅10−3 mmolL−1cmeas=3.38⋅10−3 mmolL−1.

The mass of iron in the solution is given by
mFe=cmeas⋅MFe⋅V=0.00378 mg
mFe=cmeas⋅MFe⋅V=0.00378 mg
with the volume V=0.02 LV=0.02 L and molar mass MFe=55.845 gmol−1MFe=55.845 gmol−1.