The number of pairs of the solution having the same value of the...

We know,
$\pi = iCRT$

$\pi ∝ iC$

A. $0 . 500M{C}_{2}{H}_{5}OH ( aq ) \left(iC = 1 \times 0 . 5 = 0 . 5\right)$ and $0 . 25MKBr ( aq )\left(iC = 2 \times 0 . 25 = 0 . 5\right)$

B. $0 . 100{M}_{}{K}_{4}\left[Fe ( CN{)}_{6}\right] ( aq ) \left(iC = 5 \times 0 . 1 = 0 . 5\right)$ and 0 . 100M {FeSO}_{4}{\left({NH}_{4}\right)}_{2}{SO}_{4} ( aq )\left(iC = 5 \times 0 . 1 = 0 . 5\right)

C. $0 . 05M{K}_{4}\left[Fe ( CN{)}_{6}\right]\left(iC = 5 \times 0 . 05 = 0 . 25\right)$ (aq)$and 0 . 25MNaCl\left(iC = 2 \times 0 . 25 = 0 . 5\right) ( aq )$

D. $0 . 15MNaCl ( aq ) \left(iC = 2 \times 0 . 15 = 0 . 3\right)$ and 0 . 1M{BaCl}_{2} ( aq )\left(iC = 3 \times 0 . 1 = 0 . 3\right)

E. $0 . 02MKCl . {MgCl}_{2} . 6{H}_{2}O ( aq ) \left(iC = 5 \times 0 . 02 = 0 . 1\right)$ and 0 . 05M KCl ( aq )\left(iC = 2 \times 0 . 05 = 0 . 1\right)