In acidic medium, the redox reaction between potassium permanganate and hydrogen sulphide is:
\[ 2KMnO_4 + 5H_2S + 3H_2SO_4 \rightarrow 2MnSO_4 + 5S + 8H_2O + K_2SO_4 \]
From the balanced reaction, 2 moles of KMnO\(_4\) react with 5 moles of H\(_2\)S.
So, for 1 mole of H\(_2\)S, the required moles of KMnO\(_4\) = \( \frac{2}{5} = 0.4 \)
0.4