CHEM 3201K TEST 4 ame Javen Sades -Date Part 1 (30 points) Consider-(aq) + Mets)

Question

CHEM 3201K TEST 4 ame Javen Sades -Date Part 1 (30 points) Consider-(aq) + Mets)--Mgraal +bus) F 96485 R-8.314 1. Is the above a REDOX reaction? 2. what has been oxidized? .1e5 3. What has been reduced? 4. What is the oxidizing agent? 5. What is the reducing agent? 6, what is the anode reaction? 7. What is the cathode reaction? 8. Calculate the Eot cuse he 9. Is this reaction spontaneous? 10. Calculate the equilibrium constant, K at 25 Which of the following is(are) REDOX reactions? 12. Pb(NO12(aq) + 2HO (aq)PCL(s) + 2HNOs(aa) 13. Mg(s) + 2HCl(aq) MgCh(aq) +H|g) 15. Cacols) CaO(s) + colg) IS

Explanation / Answer

1. Yes, this is a redox reaction. (How and why will be shown below)

Zn2+ + 2e- ---> Zn ---------(1)

Mg ---> Mg2+ + 2e- ---------(2)

2. The 2nd equation is the oxidation one. Mg is been oxidized as one who gets oxidized looses electrons.

3. Zn is being reduced as it gains electrons.

4. The oxidizing agent is the one which gets reduced by gaining electrons. Hence here it is Zn as it gains 2 electrons.

5. The reducing agent is Mg as it looses 2 electrons.

6. The electrode at which oxidation takes place is known as the anode. Hence here the anodic reaction is Mg ---> Mg2+ + 2e-

7. The electrode at which reduction take place is called the cathode. Hence here the cathodic reaction is Zn2+ + 2e- ---> Zn

8. Ecell=Ered+Eox

Ered = -0.76V

Eox = 2.37V

Mg2+ + 2e- --->Mg Ered = -2.37V

Mg ---> Mg2+ + 2e- Eox = 2.37V

Therefore Eocell = -0.76+(-2.37) = 1.61V

9. The redox reaction between Zn and Mg2+ is spontaneous. This is due to the difference in potential energy between the two substances. The difference in potential energy between the anode and cathode dictates the direction of electronic movement. Electrons move from areas of higher potential energy to areas of lower potential energy. In this case, the anode has a higher potential energy; electrons therefore move from anode to cathode. The potential difference between the two electrodes is measured in units of volts. One volt (V) is the potential difference necessary to generate a charge of 1 coulomb (C) from 1 joule (J) of energy.

10. lnK=nFE0cell / RT, n= 2 electrons

= 2 x 96485 x 1.61 / 8.314 x 298

= 310681.7 / 2477.572

lnK = 125.4

log K = 125.4 / 2.303 = 54.4

K = antilog 54.4 = 2.5 x 1054 at 25C

Redox (short for reduction–oxidation reaction) (pronunciation: /rdks/ redoks or /ridks/ reedoks[1]) is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a reduction process and a complementary oxidation process. Hence 13, 14, 15 are the redox reaction where both cation and anions change its oxidation states.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.