Solution:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations.
o According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
o The law of conservation of mass is useful for a number of calculations and can be used to solve for unknown masses, such the amount of gas consumed or produced during a reaction.
Thus the required right answer is B.