UNIT 6 REVIEW

Multiple Choice

Which of the following best describes the significance of understanding acid-base, precipitation, and redox reactions in everyday life?

• They help us predict weather patterns.

• They allow us to understand and control chemical changes in our environment and bodies.

• They are only important for laboratory experiments.

• They are mainly used for cooking.

Multiple Choice

Which situation best shows a chemical reaction in daily life?

• A. Ice melting in a glass on a hot day
  

• B. Sugar dissolving in water
  

• C. A candle burning and producing heat and light
  

• D. Water freezing in the freezer

Multiple Choice

Which type of chemical reaction involves ions switching between two compounds to form two new compounds?

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

Multiple Choice

Which of the following is evidence that a chemical reaction has taken place?

• A. Ice melting into liquid water
  

• B. Sugar dissolving in tea
  

• C. Bubbles forming when two substances are mixed
  

• D. Water boiling on a stove

Multiple Select

Which of the following are types of chemical reactions?

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

Multiple Choice

Precipitation Reaction

Which reaction produces a precipitate?

• A. HCl + NaOH → NaCl + H₂O
  

• B. AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)
  

• C. CH₄ + 2O₂ → CO₂ + 2H₂O
  

• D. 2H₂O → 2H₂ + O₂

Multiple Choice

In the reaction below, which substance is the precipitate?

BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)

• A. BaCl₂
  

• B. Na₂SO₄
  

• C. BaSO₄
  

• D. NaCl

Multiple Choice

Identify the reaction type:
🔥 CH₄ + 2O₂ → CO₂ + 2H₂O

• A. Synthesis
  

• B. Decomposition
  

• C. Combustion
  

• D. Double Replacement

Multiple Choice

Which type of reaction is shown below?

2H₂ + O₂ → 2H₂O

• A. Synthesis
  

• B. Decomposition
  

• C. Combustion
  

• D. Double Replacement

Multiple Choice

What reaction is shown in this chemical equation?

• water being formed in the air

• fructose being made in a plant

• your body breaking down a carbohydrate

• baking soda and vinegar reaction

Multiple Choice

Identify the type of chemical reaction

• Synthesis

• Decomposition

• Single replacement

• Double replacement

• Combustion

Multiple Choice

Acid + Base → ___ + Water

• Salt
• Oxygen

• Sodium

• Acid

Multiple Choice

Identify the Neutralization Reaction

Which equation represents an acid–base neutralization reaction?

• A. Zn + 2HCl → ZnCl₂ + H₂
  

• B. HCl + NaOH → NaCl + H₂O
  

• C. 2H₂ + O₂ → 2H₂O
  

• D. CaCO₃ → CaO + CO₂

Multiple Select

Which substances are always produced in an acid–base neutralization reaction?

• ☐ Hydrogen gas
  
  

• ☐ Water
• ☐ A salt
• ☐ Oxygen gas

Multiple Choice

Which indicator turns blue in a base and red in an acid?

• Phenolphthalein

• Universal indicator

• Litmus paper

• Bromothymol blue

Multiple Choice

Which of the following best describes a precipitation reaction?

• A reaction in which two or more substances combine to form a single new compound.

• A reaction where electrons are transferred between reactants; involves oxidation and reduction.

• A reaction that forms an insoluble solid when two solutions are mixed.

• A reaction where an acid and a base react to form water and a salt.

Multiple Choice

Which part of a zinc-carbon battery is oxidized during the redox reaction?

• Zinc case

• Carbon rod

• Electrolyte paste

• Plastic casing

Multiple Select

Which of the following are evidence of an acid-base reaction? Select all that apply.

• Formation of water and a salt

• Production of a gas like oxygen

• Neutralization of acidic and basic properties

• Color change when using an indicator

Multiple Choice

Which of the following best explains why a chemical equation must be balanced?

• To show that energy is being created.

  .

• B.

  To satisfy the Law of Conservation of Mass.

  That's right!

  This law states that matter cannot be created or destroyed, meaning the number of atoms must stay constant.

• C.

  To ensure the reaction happens quickly.

• D.

  To change the identity of the atoms involved

Multiple Choice

What are the correct coefficients to balance the following combustion reaction?
C₃H₈ +__ O₂   ------ 3CO₂ + 4H₂O

• 7

• 5

• 10

• 3

Multiple Choice

Identify the type of reaction shown here:
2NaOH(s)------- Na₂O(s) + H₂O(g)

• Single Replacement

• Decomposition

• Combustion

• Synthesis

Multiple Choice

If 100.00 g of water and 20.00 g of salt are mixed in a beaker that weighs 77.25 g, what is the total mass of the beaker and its contents after mixing?

• 120.00 g

• 177.25 g

• 97.25 g

• 197.25 g

Multiple Choice

Which set of coefficients balances this equation?
_PbS + _O₂ ------   2PbO + 2SO₂

• 2, 2

• 1, 2

• 2, 3

  
  

• 1, 3

Multiple Choice

What are the products of a neutralization reaction between sulfuric acid H₂SO₄ and magnesium hydroxide Mg(OH)₂?

• Hydrogen gas and magnesium sulfate

• B.

  Magnesium sulfate and water

• C.

  Magnesium sulfide and oxygen

• D.

  Magnesium and sulfuric oxide

Multiple Choice

Which of these represents a balanced synthesis reaction for making potassium oxide?

• K + O₂ ---- KO₂

• 2K + 2O ---- K₂O₂

• K + O ---- KO

• 4K + O₂ ---- 2K₂O

Multiple Choice

In a precipitation reaction, what is the physical state of the 'precipitate' product?

• Liquid

• Solid

• Aqueous

• Gas

Multiple Choice

Which of the following is common to all oxidation-reduction (redox) reactions?

• They only happen in the presence of oxygen.

• They must involve an acid and a base.

• Formation of water as a product.

• Transfer of electrons between reactants

Multiple Choice

Oxidation

Which statement best describes oxidation?

• A. Gain of electrons
  

• B. Loss of electrons
  

• C. Gain of protons
  

• D. Loss of neutrons

Multiple Choice

Identify the Redox Reaction

Which reaction is an oxidation–reduction (redox) reaction?

• A. HCl + NaOH → NaCl + H₂O
  

• B. AgNO₃ + NaCl → AgCl + NaNO₃
  

• C. Zn + CuSO₄ → ZnSO₄ + Cu
  

• D. CaCO₃ → CaO + CO₂

Multiple Choice

In the reaction below, which substance is oxidized?

Zn + CuSO₄ → ZnSO₄ + Cu

• A. Zn
  

• B. Cu
  

• C. SO₄
  

• D. CuSO₄