Plants cell have chloroplast which has green pigment known as chlorophyll. A plant photosynthesize because of this green pigment only. Chlorophyll is responsible for capturing sunlight and carbon dioxide from atmosphere and converting it into usable chemical energy such as glucose along with release of oxygen. Glucose acts as food source not only for plants but several other dependent organisms.
An animal cell do not has this chloroplast and hence unlike plant it is not able to produce its food.
On the prodcuts side (right) Chlorine and Hydrogen already had 2 coefficents to start with. So you needed to change your reactant Chlorine and Hydrogren to two also.
