Final answer:
The equation (a) is balanced, (b) is unbalanced, (c) is balanced, and (d) is unbalanced.
Step-by-step explanation:
a. KOH + HBr - kBr + H₂O
This equation is balanced as there is an equal number of atoms on both sides.
b. 2KCI - K+ Cl₂
This equation is unbalanced as there are two potassium atoms on the left side and one on the right side.
c. Zn + HCl - ZnCl₂ + H₂
This equation is balanced as there is an equal number of atoms on both sides.
d. 2H₂O -2H₂ + O₂
This equation is unbalanced as there are four hydrogen atoms on the left side and only two on the right side. There is also an excess of oxygen atoms on the left side.