JEE Advanced 2015 Paper 1

If th freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex(which behaves as a strong electrolyte is) -0.0558°C.the number of chlorides(s) in the coordination sphere of the complex is
[Kf‌of water=1.86K‌kg‌mol−1]