Arranging Metals in Order of Increasing Reducing Power:

The reducing power of a metal can be determined by its standard electrode potential. A metal with a more negative standard electrode potential will have a higher reducing power. In this case, we have the following standard electrode potentials:

- Mg2+/Mg = -2.37 V
- Hg2+/Hg = 0.79 V
- Cr3+/Cr = -0.74 V
- Ag/Ag = 0.80 V
- K/K = -2.93 V

To arrange the metals in order of increasing reducing power, we need to consider their standard electrode potentials. The metal with the least negative (or most positive) standard electrode potential will have the lowest reducing power, while the metal with the most negative standard electrode potential will have the highest reducing power.

Arranging the Metals:
1. Potassium (K): K/K = -2.93 V
- Potassium has the most negative standard electrode potential, indicating the highest reducing power.

2. Magnesium (Mg): Mg2+/Mg = -2.37 V
- Magnesium has a less negative standard electrode potential compared to potassium, indicating a lower reducing power than potassium.

3. Chromium (Cr): Cr3+/Cr = -0.74 V
- Chromium has a less negative standard electrode potential compared to magnesium, indicating a lower reducing power than magnesium.

4. Silver (Ag): Ag/Ag = 0.80 V
- Silver has a positive standard electrode potential, indicating a lower reducing power than chromium.

5. Mercury (Hg): Hg2+/Hg = 0.79 V
- Mercury has a slightly lower positive standard electrode potential compared to silver, indicating the lowest reducing power among the metals.

Summary:
- The metals arranged in increasing order of reducing power are: Mercury (Hg) < silver="" (ag)="" />< chromium="" (cr)="" />< magnesium="" (mg)="" />< potassium="" />
- Potassium has the highest reducing power, while mercury has the lowest reducing power.
- The reducing power of a metal is determined by its standard electrode potential, with more negative values indicating higher reducing power.

K+>mg2+>cr3+>hg2+>ag+