Question

1.What mode of decay is probable for 41/18 Ar ? What mode of decay is probable for ? a.electron capture b. beta emission C.positron emission D.alpha emission

2.

The standard cell potential, E°_cell, for a reaction in which two electrons are transferred between the reactants is +1.33 V. Calculate the standard free energy change, ΔG°, in kJ for this reaction and determine if it is spontaneous or nonspontaneous at 25°C.

A.−2.57 × 10² kJ, nonspontaneous B. −2.57 × 10² kJ, spontaneous C. −1.28 × 10² kJ, spontaneous D. +2.57 × 10² kJ, nonspontaneous

3. List the given metal ions in order of increasing strength as oxidizing agents, based on the following standard reduction potentials, E°_red .

A.	Al3+ < Fe2+ < Zn2+ < Ag+
B.	Ag+ < Fe2+ < Zn2+ < Al3+
C.	Zn2+ < Fe2+ < Ag+ < Al3+
D.	Al3+ < Zn2+ < Fe2+ < Ag+

Answer 1

Answer 1)

41/18Ar23 disintegrates by beta minus decay to excited levels and ground state levels of K-41, 41/19K22.

Correct optionis B: beta emission

Answer 2)

Given that, E°_cell = +1.33 V and n = 2, T = 25^oC = 298.15K,

F = Faraday's constant = 96,485 C/mol

DeltaG^o = -nFE°_cell

DeltaG^o = -2 × 96,485 C/mol × (+1.33 V)

DeltaG^o = -256650.1 J = -256.650 KJ

DeltaG^o = -256.650 KJ = -2.56 × 10² KJ

Since delta G is negative reaction is spontaneous. Option B is correct.

Answer 3)

Correct answer for this question is option D

Al³⁺ < Zn²⁺ < Fe²⁺ < Ag⁺

Ag⁺ + e^-   à Ag_(s) -------------E^o = 0.80V

Fe²⁺ + 2e^-   à Fe_(s)------------- E^o = -0.45V

Zn²⁺ + 2e^-   à Zn_(s)------------- E^o = -0.76V

Al³⁺ + 3e^-   à Al_(s)------------- E^o = -1.66V

A.	Al3+ < Fe2+ < Zn2+ < Ag+
B.	Ag+ < Fe2+ < Zn2+ < Al3+
C.	Zn2+ < Fe2+ < Ag+ < Al3+
D.	Al3+ < Zn2+ < Fe2+ < Ag+