Question

1.5g of magnesium ribbon burns completely in one gram of oxygen to form magnesium oxide.what mass of magnesium oxide is formed.define the law which helped you to find the weight of magnesium oxide.

Answer 1

2.5 gram, law of conservation of mass.
here the magnesium completely burns so we need not see the law of constant proportions

Answer 2

Answer: 2.5 g, Law of conservation of mass

Explanation:

$2Mg+O_2\rightarrow 2MgO$

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of the products formed must be same as the mass of the reactants taken in a balanced chemical equation.

Given mass of reactants = mass of magnesium + mass of oxygen = 1.5 g + 1.0 g= 2.5 g

Thus mass of products = mass of reactants = 2.5 g