Question

Which of the following equations best represents the meaning of the law of conservation of mass?

Answer 1

Answer:mass of reactants = mass of products

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

$H_2+O_2\rightarrow 2H_2O$

mass of hydrogen= 4 g

Mass of oxygen = 32 g

mass of water = $2times 18=36g$

Thus mass or reactants =

Mass of hydrogen + mass of oxygen= 4+32= 36 g

Mass of product = mass of water = 36 g

Thus the total mass of reactants is equal to the total mass of products.

Answer 2

The correct answer is a mass of products = mass of reactants.  

In a chemical reaction, the law of conservation of mass states that the entire mass of reactants is equivalent to the entire mass of products. For example, the mass of sodium and the mass of chlorine, which reacts with the sodium is equivalent to the product sodium chloride's mass. As in the chemical reaction, the atoms are only rearranged, there must be an equal number of chlorine and sodium atoms in both the products and the reactants.