Answer:
A. Pb(OH)2 + 2HCl → 2H2O + PbCl2
Step-by-step explanation:
In a balanced reaction, the amount of different atoms in the products must be equal to number of atoms in reactants. With the equations of the problem:
A. Pb(OH)2 + 2HCl → 2H2O + PbCl2
There is 1 atom of Pb in reactants and products.
2 atoms of O in both sides.
4 atoms of H
And 2 atoms of Cl
That means this reaction is balanced
B. 2Pb(OH)2 + HCl → H2O + 2PbCl2
2 atoms of Pb
4 atoms of O in reactants but just 1 in products.
As the amount of oxygen is not equal for reactants and products we can say the reaction is unbalanced.
And right choice is A.