- Chlorophyll contains magnesium (Mg), not cobalt (Co), so the combination A is mismatched.
- Water hardness is treated using EDTA, which is correct.
- Photography involves silver salts like \( \text{AgCl} \), not \( [\text{Ag(CN)}_2] \), so the combination C is mismatched.
- Wilkinson catalyst is indeed \( [(Ph_3P)_3 \text{RhCl}] \), which is correct.
- D-Penicillamine is a chelating ligand, which is correct.
Thus, the mismatched combinations are A and C.
Calculate the potential for half-cell containing 0.01 M K\(_2\)Cr\(_2\)O\(_7\)(aq), 0.01 M Cr\(^{3+}\)(aq), and 1.0 x 10\(^{-4}\) M H\(^+\)(aq).

A square loop of sides \( a = 1 \, {m} \) is held normally in front of a point charge \( q = 1 \, {C} \). The flux of the electric field through the shaded region is \( \frac{5}{p} \times \frac{1}{\varepsilon_0} \, {Nm}^2/{C} \), where the value of \( p \) is: