separate the atoms from the molecules and give them charges
H2S = 2 H+ + S^-2
double replacement reaction.
AB + CD = AD + CB
Hydrogen sulfide gas is bubbled through excess potassium hydroxide solution, but you only put H2S + 2OH– → S2– + 2H2O
H2S + KOH -> K2S + H2O
to here...
H2S + 2OH– → S2– + 2H2O
AB + CD = AD + CB
H2=A;S=B;K=C;(OH)=D
[AD]=H2+(OH)=H2O
[CB]=K+S=KS
