Question

SnO2 + H2 → Sn + H2O

What is true about this chemical reaction?

A. It is balanced because the mass of the reactants (number of atoms) is equal to the mass of the products (number of atoms).

B. It is unbalanced because the mass of the reactants (number of atoms) is greater than the mass of the products (number of atoms).

C. It is unbalanced because the mass of the reactants (number of atoms) is less than the mass of the products (number of atoms).

D. It is balanced because the number of reactants (number of atoms) is equal to the number of products (number of atoms).

Answer 1

The chemical reaction SnO2 + H2 → Sn + H2O is unbalanced. It becomes balanced by adding a coefficient of 2 to H2O, making the reaction SnO2 + 2H2 → Sn + 2H2O, satisfying the law of conservation of mass.

Step-by-step explanation:

The chemical reaction SnO2 + H2 → Sn + H2O is unbalanced because the number of atoms for each element is not the same on both sides of the equation. The reactants have one Sn atom, two O atoms, and two H atoms; while the products have one Sn atom, one O atom, and two H atoms (if we only assume one molecule of H2O is formed). To balance the equation, we would change the coefficient for H2O to 2, yielding: SnO2 + 2H2 → Sn + 2H2O. Here we have one Sn atom, two O atoms, and four H atoms on both sides, complying with the law of conservation of mass.

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