Question

Which statement best describes the equation CaCO3 + 2HCl → CaCl2 + CO2 + H2O?

CaCO3 is a reactant; it is present before the reaction occurs.
CaCl2 is a reactant; it is present before the reaction occurs.
CO2 is a reactant because it is most likely a gas.
H2O is a reactant because it is most likely a liquid.

Answer 1

CaCO3 is a reactant; it is present before the reaction occurs.

Explanation: In a chemical equation, substances written on the left side are reactants (present before the reaction) and those on the right are products (formed by the reaction). Here CaCO3 appears on the left.