No, the chemical reaction between C2H4O2 (acetic acid) and NaHCO3 (sodium bicarbonate) is not a physical change. It is a chemical change because it involves the formation of new substances with different properties from the original reactants.

The reaction between acetic acid and sodium bicarbonate produces carbon dioxide gas, water and sodium acetate. These products have different chemical properties and composition compared to the starting materials. The reaction is represented by the following equation:

C2H4O2(aq) + NaHCO3(s) → CO2(g) + H2O(l) + CH3COONa(aq)