0.0100 M K2Cr2O7 14.92 mL 적정

0.0100 M K2Cr2O7 14.92 mL 적정

 

 

정제 한 개를 물 10.0 mL에 녹여

0.0100 M K2Cr2O7 용액 14.92 mL로 적정하였을 때

 

 

Iron(II) sulfate is a soluble ionic compound

added as a source of iron in vitamin tablets.

Determine the mass of iron (mg) in one tablet

that has been dissolved in 10.0 mL of water

and titrated with 14.92 mL of 0.0100 M K2Cr2O7 solution.

The net ionic equation is:

Cr2O7^2-(aq) + 6Fe^2+(aq) + 14H^+(aq)

→ 2Cr^3+(aq) + 6Fe^3+(aq) + 7H2O(l)

 

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(0.0100 mol/L) (14.92/1000 L) = 0.0001492 mol K2Cr2O7

= 0.0001492 mol Cr2O7^2-

 

 

 

Cr2O7^2- : Fe^2+ = 1 : 6 = 0.0001492 mol : ? mol

 

? = 6 × 0.0001492 = 0.0008952 mol Fe^2+

 

 

 

Fe의 몰질량 = 55.845 g/mol 이므로,

0.0008952 mol × (55.845 g/mol) = 0.04999 g Fe

 

 

 

답: 49.99 mg