Chemical Reactions Test Review

What happens to the number of atoms in a reaction?

• They stay the same in both the reactants & products

• They increase in products

• They decrease in reactants

• They decrease in products

Which of the following lists all the elements that are present in a molecule of potassium carbonate, K₂CO₃ ?

• Arbon and Oxygen
  

• phosphate and calcium
• potassium, carbon, and oxygen
• phosphorus, oxygen, and calcium

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₃PO₄
• H₂SO₄
• HCIO₃
• H₂O

Which of the following equations follows the law of conservation of mass?

• 3H₂O → 3H₂ + 3O₂
• C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
• C + 4H₂→ CH₄
• 2Na + Cl → NaCl

NaOH + HCl --> NaCl + H₂O Identify the reactants in the chemical equation above.

• NaOH and HCl
• NaCl and H₂O
• HCl and H₂O
• HCl and NaCl

The Law of Conservation of Mass states

• that matter exists in all states and reacts the same

• that matter can only be changed into new substances by introducing a catalyst

• that matter exists in the same state throughout any chemical change

• that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

The following is what type of reaction:
PbCl₂ + AgNO₃ → Pb(NO₃)₂ + AgCl

• Synthesis
• Decomposition
• Single Replacement
• Double Replacement

The following is what type of reaction:
NH₃ + HCl  → NH₄Cl

• Synthesis
• Decomposition
• Single Replacement

• Double Replacement

What type of chemical reaction is this?
Al(OH)₃ → Al₂O₃  + H₂O

• Decomposition
• Combustion
• Synthesis
• Single Replacement 

3Ca + 2AlCl₃ --> 3CaCl₂ + 2Al

• Synthesis
• Decomposition
• Single Replacement

• Double Replacement