5.05 Decomposition Reactions

Which of the following is a decomposition reaction?

• 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O

• H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

• 6NaNO₃ → 6NaNO₂ + 3O₂

• 4P + 5O₂ → 2P₂O₅

Which of the following could make a decomposition reaction occur?

• time

• nothing needed for most to proceed

• heat or light

Tags

NGSS.MS-PS3-4

Which of the following reactions is the opposite of a decomposition reaction?

• electrolysis of water

• synthesis

• combustion

• explosion

What would most likely be the products of the decomposition of HI (hydrogen iodide)?

• hydrogen only

• hydrogen, iodine, and carbon dioxide

• iodine only

• hydrogen and iodine

Tags

NGSS.MS-PS1-5

Consider this reaction: 2HgO ==> 2Hg + O₂. Which of the following is the best explanation for why this reaction is a decomposition reaction?

• This is a decomposition reaction because the equation is balanced.

• This is a decomposition reaction because there is only one reactant.

• This is a decomposition reaction because there are two products.

• This is a decomposition reaction because oxygen is one of the reactants.