Chemical Reactions Quiz

What is a chemical reaction?

• A process that only changes the state of matter

• A process where atoms rearrange to form new substances

• A mixture of physical and chemical changes

• Atoms disappearing and reappearing

Which of the following is always true in a chemical reaction?

• New atoms are created

• Atoms disappear

• Atoms are rearranged

• Atoms become energy

Which of the following is an example of a chemical reaction?

• Boiling water

• Melting ice

• Burning wood

• Freezing juice

What does the arrow in a chemical equation represent?

• Equality

• Reactants

• Products

• Direction of the reaction

In the equation: 2H₂ + O₂ → 2H₂O, what are the reactants?

• H₂O

• H₂ and O₂

• H only

• O₂ and H₂O

Which equation is balanced?

• H₂ + O₂ → H₂O

• Na + Cl₂ → NaCl

• 2H₂ + O₂ → 2H₂O

• H₂O → H₂ + O₂

What law is demonstrated when chemical equations are balanced?

• Law of gravity

• Law of conservation of mass

• Law of energy loss

• Law of acceleration

Which symbol means a substance is a gas in a chemical equation?

• (l)

• (g)

• (aq)

• (s)

In a synthesis reaction, two or more substances:

• Break down

• Combine to form one product

• Exchange ions

• Form a gas and a precipitate

Which reaction shows decomposition?

• HCl + NaOH → NaCl + H₂O

• 2H₂O₂ → 2H₂O + O₂

• AgNO₃ + NaCl → AgCl + NaNO₃

• CH₄ + 2O₂ → CO₂ + 2H₂O