`a FeCl_(3)+bH_(2)S rarr FeCl_(2)+HCl+S` after balancing the reaction, find the values of `a` & `b`?

In the reaction 2FeCl_(3)+H_(2)Srarr2FeCl_(2)+2HCl+S

The raction 2FeCl_(3) + SnCl_(2) rarr 2FeCl_(2) + SnCl_(4) is an example of

FeCl_(3).6H_(2)O is actually:

2FeCl_(3)+SnCl_(2)to2FeCl_(2)+SnCl_(4) is an example of

FeS +HCl rarr FeCl_(2)+X X+F_(2)rarr Y+HF X+Cl_(2)rarr Z+HCl Oxidation states of central atom in X, Y and Z are respectively