Reactions Checkpoint

Answer explanation

The balanced equation for the combustion of methane is CH_4 + 2O_2 → CO_2 + 2H_2O. This shows one molecule of methane reacting with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water.

Tags

TX.112.43.C.9.A.

Answer explanation

In a single replacement reaction, zinc (Zn) displaces hydrogen (H) from hydrochloric acid (HCl). The products are zinc chloride (ZnCl_2) and hydrogen gas (H_2), making the correct answer ZnCl_2 + H_2.

Tags

TX.112.43.C.9.A.

Nora and Mason are in a chemistry lab, and they are mixing different substances. Which of the following reactions are they observing if they are witnessing a synthesis reaction?

Answer explanation

The reaction 2H2 + O2 → 2H2O is a synthesis reaction because it combines two reactants (hydrogen and oxygen) to form a single product (water). The other options represent decomposition or combustion reactions.

Tags

TX.112.43.C.9.A.

Answer explanation

The reaction is already balanced as written: one calcium atom, one carbon atom, and three oxygen atoms on both sides. Therefore, the correct choice is CaCO₃ → CaO + CO₂.

Tags

TX.112.43.C.9.A.

Answer explanation

The combustion of ethane (C2H6) in oxygen produces carbon dioxide (CO2) and water (H2O) as the main products, following the complete combustion reaction. Therefore, the correct answer is CO2 and H2O.

Tags

TX.112.43.C.9.A.

• Decomposition

• Single Replacement

• Synthesis

• Combustion

Answer explanation

The reaction 2Na + Cl_2 → 2NaCl involves the combination of sodium and chlorine to form sodium chloride. This is a synthesis reaction, where two or more reactants combine to form a single product.

Tags

TX.112.43.C.9.A.

Answer explanation

The decomposition of 2KClO3 produces potassium chloride (KCl) and oxygen (O2). Balancing the reaction gives 2KCl + 3O2, making this the correct product of the decomposition.

Tags

TX.112.43.C.9.A.

Olivia and Priya are conducting a chemistry experiment. They want to know which of the following is a balanced equation for the single replacement reaction between aluminum and copper(II) sulfate. Can you help them figure it out?

Answer explanation

The balanced equation for the reaction between aluminum and copper(II) sulfate is 2Al + 3CuSO4 → Al2(SO4)3 + 3Cu. This shows that two aluminum atoms replace three copper ions, forming aluminum sulfate and copper.

Tags

TX.112.43.C.9.A.

• Synthesis

• Decomposition

• Single Replacement

• Combustion

Answer explanation

The equation 2HgO → 2Hg + O2 shows a compound (HgO) breaking down into simpler substances (Hg and O2). This is characteristic of a decomposition reaction, where one substance decomposes into two or more products.

Tags

TX.112.43.C.9.A.

Answer explanation

The combustion of propane (C3H8) in oxygen produces carbon dioxide (CO2) and water (H2O) as the main products, following the complete combustion reaction. Thus, the correct answer is CO2 and H2O.

Tags

TX.112.43.C.9.A.