Claiming Conservation Quick Check

Which statement accurately describes what happens in a reaction when reactants become products?

Reactant bonds break and atoms rearrange to form new product combinations.

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?

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

Hydrogen (H2) and oxygen (O2) combine to make water (H2O) in the following equation. 6H2 + 3O2 → ?H2O How many water molecules would be produced?

six

Methane (CH4) and oxygen (O2) combine to make carbon dioxide (CO2) and water (H2O) in the following unbalanced equation. CH4 + O2 → CO2 + H2O How many oxygen molecules are necessary in order to complete this reaction?

two

In photosynthesis, carbon dioxide (CO2) and water (H2O) combine to form the sugar glucose (C6H12O6) in the following reaction: 6CO2 + 6H2O → C6H12O6 + ? Assuming this equation is balanced, which part is missing from the product side?

12 oxygen atoms