Question

use the equation for the formation of water to answer the question.
2h₂ + o₂ → 2h₂o
elements such as oxygen and hydrogen naturally exist as diatomic molecules (i.e., in a paired-atom form). does the equation for the formation of water violate the law of conservation of mass? why or why not?
(1 point)
○ yes, it does because the diatomic oxygen molecule is not present on both sides of the equation
○ no, it does not because the number and mass of atoms are conserved even though the number of molecules is not.
○ yes, it does because there are two oxygen atoms in the reactants and only one in the product.
○ no, it does not because there are two water molecules, so the bonds within the diatomic molecules were not broken

Explanation:

To determine if the equation \(2H_2 + O_2
ightarrow 2H_2O\) violates the law of conservation of mass, we analyze the number of atoms on each side.

• Reactants (left side):
• Hydrogen: \(2 \times 2 = 4\) atoms (from \(2H_2\)).
• Oxygen: \(2\) atoms (from \(O_2\)).
• Products (right side):
• Hydrogen: \(2 \times 2 = 4\) atoms (from \(2H_2O\)).
• Oxygen: \(2 \times 1 = 2\) atoms (from \(2H_2O\)).

The law of conservation of mass states that the number and mass of atoms must be conserved in a chemical reaction (molecules can change, but atoms cannot be created or destroyed). Here, the number of H and O atoms is the same on both sides.

Now, we evaluate the options:

• First option: Incorrect. The law of conservation of mass is about atoms, not molecules (like \(O_2\)) being present on both sides.
• Second option: Correct. The number (and mass) of atoms (H: 4, O: 2) is conserved, even though the number of molecules (reactants: \(2 + 1 = 3\); products: \(2\)) is not.
• Third option: Incorrect. The product \(2H_2O\) has \(2 \times 1 = 2\) O atoms, matching the reactant \(O_2\) (2 O atoms).
• Fourth option: Incorrect. The reaction involves breaking bonds in \(H_2\) and \(O_2\) to form \(H_2O\), so bonds are broken.

Answer:

B. No, it does not because the number and mass of atoms are conserved even though the number of molecules is not.