Answer:
D . 20 grams reactant U + 3 grams reactant V → 23 grams product W
Explanation:
Law of conservation of mass states:
The mass of a closed system (As a reaction), is neither created or destroyed.
That is, the mass of reactants is equal to mass of products.
A. In reaction A 22g of reactants produce 9g of products. This reaction doesn't illustrates the law of conservation of mass.
B. 10g reactant produce 25g of products. This reaction doesn't illustrates the law of conservation of mass.
C. 19g of reactants produce 180g of products. This reaction doesn't illustrates the law of conservation of mass.
D. 23g of reactants produce 23g of products. -This is the reaction that best illustrates the Law of Conservation of Mass.