There are two reactants in a chemical equation and one product. The mass of the product is 30 g. The mass of the first reactant is 15 g. What must the mass of the second reactant be, if the equation is to follow the law of conservation of mass?
Answers
Answer :
The law of conservation of mass - mass can neither be created nor destroyed.
Now, what is given in the question? It's given that there are two reactants in a chemical equation. And it's also given that only one product is obtained.
Let's mention mass of the reactant and the product first.
• Reactant 1 = 15 g
• Reactant 2 = X
• Product = 30 g
Reactant 1 + Reactant 2 = Product
That is ,
15 g + X = 30 g
X = 30 - 15
X = 15
So, the mass of the second reactant is 15g.
• Law of conservation of mass :
Mass of the reactants should be equal to the mass of the product.
Reactants = Product.
As per law of conservation of mass, the total mass of the system subjected under reaction remains constant, at any point of time. In other words, and for solving this particular problem, we should know that the total amount of reactant subjected to reaction, is equal to the total amount of product obtained after 100% completion of reaction.
The mass of product is 30 g. Mass of first reactant is 15 g. There are two reactants.
By applying conservation of mass and human logic, one can easily decipher that
Mass of second reactant = mass of product - mass of first reactant
Which gives, mass of second reactant = 30 - 15 = 15 g.