32.18 g K2Cr2O7 1.000 L 19.93 mL Cu^+ 250.0 mL

32.18 g K2Cr2O7 1.000 L 19.93 mL Cu^+ 250.0 mL

 

 

Potassium dichromate in acidic solution

is used to titrate a solution of copper(I) ions,

with which it reacts according to

Cr2O7^2-(aq) + Cu^+(aq) → Cr^3+(aq) + Cu^2+(aq)

 

A potassium dichromate solution is prepared by

dissolving 32.18 g of K2Cr2O7 in water

and diluting to a total volume of 1.000 L.

A total of 19.93 mL of this solution is required

to reach the end point in a titration of

a 250.0 mL sample containing Cu^+(aq).

Determine the concentration of Cu^+ in the original solution.

 

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균형 맞춘 화학 반응식

Cr2O7^2-(aq) + 6Cu^+(aq) + 14H^+(aq) → 2Cr^3+(aq) + 6Cu^2+(aq) + 7H2O(l)

 

 

 

[공식] Cu^+ 시료 용액의 몰농도(M)

= K2Cr2O7 질량(g) / 294.18 / K2Cr2O7 부피(L) × K2Cr2O7 소비(L) × 6 / Cu^+ 부피(L)

( 참고 https://ywpop.tistory.com/21946 )

 

= 32.18 / 294.18 / 1.000 × (19.93/1000) × 6 / (250.0/1000)

= 0.05232 M

 

 

 

 

[키워드] redox Cr2O7^2- + Cu^+, redox Cu^+ + Cr2O7^2-, K2Cr2O7 적정 기준문서, Cr2O7^2- + Cu^+ + H^+ → Cr^3+ + Cu^2+ + H2O, Cr2O7^2- + 6Cu^+ + 14H^+ → 2Cr^3+ + 6Cu^2+ + 7H2O, Cr2O7^2-(aq) + 6Cu^+(aq) + 14H3O^+(aq) → 2Cr^3+(aq) + 6Cu^2+(aq) + 21H2O(l), Cr2O7^2- + 6Cu^+ + 14H3O^+ → 2Cr^3+ + 6Cu^2+ + 21H2O