Can the following problems be solved uniquely?

$($a$)$ The feed streams to an adiabatic equilibrium stage consist of liquid and vapor streams of known composition, flow rate, temperature, and pressure. Given the stage $($outlet$)$ temperature and pressure, calculate the compositions and amounts of equilibrium vapor and liquid leaving.

$($b$)$ The same as part $($a$),$ except that the stage is not adiabatic.