Question

Which of the following statements is/are not true for the reaction between MnO-4 and S2–?

• A. (A) 1 millimole of S2– is equivalent to 0.4 millimoles of MnO-4 .
• B. (B) 1 millimole of MnO-4 is equivalent to 5 millimoles of S2–.
• C. (C) 1 millimole of MnO-4 produces 2.5 millimoles of S.
• D. (D) Mn2+ and S are produced in the mole ratio 2 : 5.

Answer 1

Answer: (B)

(B) 1 millimole of MnO-4 is equivalent to 5 millimoles of S2–.

Answer 2

Explanation:
Balanced half reactions are:MnO4−+8H++5e→Mn2++4H2Os2−→s+2eSo, the balanced equation is:2MnO4−+16H++5.s2−→2Mn2++8H2O+5s1 millimole of s2− is equivalent to 2/5=0.4 millimoles of MnO4− 1 millimole of MnO4− produces 5/2=2.5 millimoles of SMn2+ and S are produced in the ratio 2: 5 Hence, the statements (1),(3) and (4) are correct.