Describing Chemical Reactions Review Questions

What is the definition of a chemical reaction?

• A process in which substances change into new substances with different properties.

• A process that involves only physical changes.

• A mixture of different substances.

• A reversible change in state.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What symbol is used to separate reactants from products in a chemical equation?

• +

• (s)

• →

• ⇋

Which of the following is a balanced chemical equation for the combustion of methane?

• CH₄ + O₂ → CO₂ + H₂O

• CH₄ + 2O₂ → CO₂ + 2H₂O

• 2CH₄ + O₂ → 2CO₂ + 2H₂O

• CH₄ + O₂ → CO + H₂O

Tags

NGSS.MS-PS1-5

In the reaction 2H₂ + O₂ → 2H₂O, what is the coefficient of O₂?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

Which of the following equations represents a balanced reaction between hydrogen and chlorine to form hydrogen chloride?

• H₂ + Cl₂ → 2HCl

• H₂ + Cl → HCl

• 2H + Cl₂ → 2HCl

• H₂ + 2Cl₂ → 2HCl₂

Tags

NGSS.MS-PS1-5

What is the balanced equation for the reaction of aluminum with oxygen to form aluminum oxide?

• 4Al + 3O₂ → 2Al₂O₃

• 2Al + O₂ → Al₂O₃

• Al + O₂ → AlO

• Al₂ + O₂ → 2AlO

Tags

NGSS.MS-PS1-5

What is the role of a catalyst in a chemical reaction?

• Slows down the reaction.

• Speeds up the reaction without being consumed.

• Changes the products of the reaction.

• Is consumed in the reaction.

In the equation 2Na(s) + Cl₂(g) → 2NaCl(s), what is the state of sodium chloride?

• Solid

• Liquid

• Gas

• Aqueous

Tags

NGSS.MS-PS1-4

Which of the following represents a balanced chemical equation for the reaction of sodium with water?

• Na + H₂O → NaOH + H₂

• 2Na + 2H₂O → 2NaOH + H₂

• Na + 2H₂O → NaOH + 2H₂

• 2Na + H₂O → 2NaOH + H₂

Tags

NGSS.MS-PS1-5

What coefficient is needed to balance the equation: H₂SO₄ + ?NaOH → Na₂SO₄ + 2H₂O?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5