Unit 3 review for final

What type of reaction occurs between an element and a compound?
Zn + 2HCl --> ZnCl₂ + H₂

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

Answer explanation

Single Replacement reaction occurs when an element replaces another in a compound, as seen in Zn + 2HCl -> ZnCl2 + H2.

What kind of reaction is this:
2H₂ + O₂ --> 2H₂O

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

Answer explanation

The given reaction is a synthesis reaction because two or more reactants combine to form a single product, which is the case here with 2H2 + O2 -> 2H2O.

What kind of reaction is this:
4Fe  +  3O₂ →   2Fe₂O₃ 

• Synthesis

• Decomposition

• Single Replacement 

• Double Replacement

Answer explanation

The given reaction is a synthesis reaction where two or more substances combine to form a more complex product, in this case, 4Fe + 3O2 -> 2Fe2O3.

What kind of reaction is this:
2H₂O₂ →2 H₂O + O₂

• Synthesis

• Decomposition

• Single Replacement 

• Combustion

Answer explanation

The given reaction 2H2O2 → 2 H2O + O2 is an example of a Decomposition reaction where a compound breaks down into simpler substances.

What kind of reaction is this:
2C₃H₇OH +9O₂ -> 6CO₂ + 8H₂O

• Double Replacement

• Combustion

• Single Replacement

• Decomposition

Answer explanation

The given reaction is a combustion reaction, where a substance reacts with oxygen to produce carbon dioxide and water. This is evident from the presence of oxygen and the formation of CO2 and H2O.

What kind of reaction is this:
Fe + CuSO₄ -> Cu + FeSO₄

• Double Replacement

• Decompostion

• Single Replacement

• Combustion

Answer explanation

The reaction Fe + CuSO4 -> Cu + FeSO4 is a Single Replacement reaction where Fe replaces Cu in the compound to form FeSO4 and Cu.

The reaction below is an example of?
AgNO₃ + NaCl → AgCl + NaNO₃

• Single Replacement

• Double Replacement

• Decomposition

• Combustion

Answer explanation

The reaction is an example of Double Replacement where the cations and anions of two compounds switch partners to form two new compounds.

What kind of reaction is this:
 CaCO₃ + Ag₂SO₄ → CaSO₄ + Ag₂CO₃ 

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Answer explanation

The reaction is a Double Replacement reaction where the cations and anions of two compounds switch places to form two new compounds.

An element plus additional element reacts to form one product is an example of which type of chemical reaction? 

• combustion

• decomposition 

• synthesis 

• single replacement

Answer explanation

The given chemical reaction involves the combination of two elements to form a single product, which is characteristic of a synthesis reaction.

Which type of reaction takes place in the presence of oxygen and produces carbon dioxide and water?

• double replacement 

• decomposition 

• combustion 

• single replacement

Answer explanation

Combustion reaction occurs in the presence of oxygen and produces carbon dioxide and water.