Since primary and secondary windings are connected magnetically you cannot separate the reactances. We can measure d.c. resistance separately but not a.c. resistance [no skin effect and proximity effect in d.c.].
The no-load impedance is the total primary impedance including leakage reactance [Xp] and main magnetic flux reactance [Xm] and the primary winding resistance [Rp].
Measuring no-load losses and load losses we may calculate the sum of a.c. resistance of both sides [Rp+R's] including core losses and tank losses -if any [Rfe].