3
QuizMultiple Choice

Describing Chemical Reactions — Quiz

Question 3 • Physical Science

Cecil writes the equation for the reaction of hydrogen and oxygen. cap h sub 2 plus cap o sub 2 rightarrow cap h sub 2 cap o Why does his teacher ask him to balance the equation by including the correct coefficients?

Answer
A
to show that atoms are conserved in chemical reactions
B
to show that atoms are created in chemical reactions
C
to show that most molecules exist in pairs
D
to show that most compounds exist in pairs

Explanation

A chemical equation must have the same number of each type of atom on both sides because atoms are conserved in a chemical reaction. For example, the balanced equation is 2H₂ + O₂ → 2H₂O: there are 4 hydrogen atoms and 2 oxygen atoms on each side. The coefficients show this conservation, so the correct choice is “to show that atoms are conserved in chemical reactions.”

AI-written and checked against the verified answer.

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