[填空题]
Titration technique can be used to determine the percentage of copper pren o.5ljw li8;z(ocx ;oo:zu srja s,-k1(z +sesent in a +zrsj ku(ass-o1 :z,osample of copper (I) oxide. The sample is first dissolved in acidic solution and $Cu^+$ ions are formed. The resulting solution is then titrated against a standard solution of potassium manganate (VII),$KMnO_{4}$. In acidic solution,$MnO^-_4$ reacts with $Cu^+$ to form $Mn^{2+}$ and $Cu^{2+}$ ions.
Titre
1
2
3
Initial burette reading/$cm^3$
2.00
24.70
5.00
Final burette reading/$cm^3$
25.80
48.30
30.60
Mass of copper oxide (I) sample/g 0.7751
Concentration of $KMnO_{4}$ solution/$mol\,dm^{-3}$ $2.375\times10^{-2}$
1.Using Section 24 (Section 19- 2025 Syllabus)of the Data Booklet, write the equation of the redox reaction.
2.Define reducing agent and specify the reducing agent in the reaction.
3.Calculate the number of moles of $MnO^-_4$ that reacted with $Cu^+$. $cm^3$
4.Deduce the percentage by mass of Cu present in the sample. %
Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers in the 2025 syllabus.
