Will award brainliest! plz check my ! how does the law of conservation of mass apply to this reaction: al + 3hcl = h2 + alcl3? a. the equation needs to be balanced. there are fewer hydrogen atoms in the equation than aluminum or chlorine. b. the law of conservation of mass has already been applied. there is an equal number of each element on both sides of the equation. c. hydrogen and chlorine need to be balanced. there is an equal amount of aluminum on each side. d. only the hydrogen needs to be balanced. there are equal numbers of aluminum and chlorine.