Which pair of ions will be most likely to react at standard state conditions?

1. a) MnO4- and Sn2+
2. b) Zn2+ and Cl-
3. c) I- and Cu
4. d) Fe3+ and Cu2+

To determine which pair of ions is most likely to react at standard state conditions, we need to consider their standard electrode potentials. The larger the difference between the standard electrode potentials, the more likely the ions are to react.

1. The standard electrode potential for MnO4- is +1.51 V, while for Sn2+ it is -0.14 V. The difference between these values is 1.65 V.

2. The standard electrode potential for Zn2+ is -0.76 V, while for Cl- it is +1.36 V. The difference between these values is 2.12 V.

3. The standard electrode potential for I- is -0.54 V, while for Cu it is +0.34 V. The difference between these values is 0.88 V.

4. The standard electrode potential for Fe3+ is +0.77 V, while for Cu2+ it is +0.34 V. The difference between these values is 0.43 V.

Based on the differences in standard electrode potentials, option b) Zn2+ and Cl- is the pair of ions most likely to react at standard state conditions, as it has the largest difference of 2.12 V.

To determine which pair of ions is most likely to react at standard state conditions, we need to consider their redox potentials or reduction potentials. The higher the difference in the reduction potentials between two ions, the more likely they are to react.

1. The reduction half-reaction for MnO4- is: MnO4- + 8H+ + 5e- -> Mn2+ + 4H2O
The reduction half-reaction for Sn2+ is: Sn2+ -> Sn
The reduction potential for MnO4-/Mn2+ is +1.51 V
The reduction potential for Sn2+/Sn is -0.14 V
The difference in reduction potentials is 1.65 V

2. The reduction half-reaction for Zn2+ is: Zn2+ + 2e- -> Zn
The reduction half-reaction for Cl- is: 2Cl- -> Cl2 + 2e-
The reduction potential for Zn2+/Zn is -0.76 V
The reduction potential for Cl-/Cl2 is +1.36 V
The difference in reduction potentials is 2.12 V

3. The reduction half-reaction for I- is: 2I- -> I2 + 2e-
The reduction half-reaction for Cu is: Cu2+ + 2e- -> Cu
The reduction potential for I-/I2 is +0.54 V
The reduction potential for Cu2+/Cu is +0.34 V
The difference in reduction potentials is 0.2 V

4. The reduction half-reaction for Fe3+ is: Fe3+ + 3e- -> Fe
The reduction half-reaction for Cu2+ is: Cu2+ + 2e- -> Cu
The reduction potential for Fe3+/Fe is -0.04 V
The reduction potential for Cu2+/Cu is +0.34 V
The difference in reduction potentials is 0.38 V

Based on the differences in reduction potentials, we can conclude that option 2, which is Zn2+ and Cl-, has the highest difference in reduction potentials (2.12 V). Therefore, Zn2+ and Cl- are the most likely pair of ions to react at standard state conditions.

Look up the values in your text and calculate the E value. + values and the reaction goes as written; negative values don't go as written.