Answer:
2 HCl + CaCO3 = CaCl2 + H2O + CO2
Step-by-step explanation:
On the right side we have 2xCl, to get the same amount we will multiply HCl on the left side by 2.
This will give us 2xH on the left side; we also have 2xH on the right side ( in H2O).
On both sides we have 1x Ca; 1x C.
On the left side we have 3XO (in CaCO3), on the right side we have 1O in H20 and 2xO in CO2, so 3x O on the right side as well.
The reaction is balanced.