Cyanide is known to inhibit the flow of electrons along the electron transport chain. How would exposure to cyanide affect the pH of the outer mitochondrial compartment (the inter - membrane space)

The pH will be very High.

Explanation:

The electron chain is responsible for generating the Proton Motive Force, which pumps H + (protons) into the inter membrane space, to lower the pH. Therefore if Cyanide inhibits the ETC, the PMF will be stopped.

Hydrogen ions will not be pumped into the inter-membrane space, to lower the pH of the medium for increase acidity. Hence, electrochemical gradient from the diffusion of H + back into the matrix will not be generated,

Energy for ATP synthesis by ATPase Enzyme will not be produced. Therefore ATP synthesis will stop.