Quiz 4/24

Which type of chemical reaction is illustrated by the formula: A + B → AB?

• Synthesis reaction

• Single displacement reaction

• Combustion reaction

• Decomposition reaction

Answer explanation

The equation A + B → AB represents a synthesis reaction, where two or more substances combine to form a single compound.

Count the number of hydrogen atoms present on the reactant side in the chemical equation: 2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O?

• 10

• 8

• 14

• 12

Answer explanation

The balanced equation shows that there are 6 hydrogen atoms on the product side. Therefore, there must be 6 hydrogen atoms on the reactant side as well. The correct answer is 12.

What is the total number of atoms present in the products of the chemical reaction: 2H₂ + O₂ → 2H₂O?

• 4

• 8

• 10

• 6

Answer explanation

The balanced equation shows that 2H₂ + O₂ → 2H₂O. On the product side, there are 6 total atoms (2 hydrogen atoms and 4 oxygen atoms).

For the chemical equation Fe + O₂ → Fe₂O₃, what is the correct coefficient to balance Fe₂O₃?

• 2

• 1

• 3

• 4

Answer explanation

To balance the equation, the coefficient 2 should be placed in front of Fe₂O₃. This ensures that there are equal numbers of Fe and O atoms on both sides of the equation.

According to the chemical reaction: 2Na + Cl₂ → 2NaCl, determine the number of moles of Na required to completely react with one mole of Cl₂.

• 1

• 4

• 3

• 2

Answer explanation

To react with 1 mole of Cl₂, 2 moles of Na are needed. Therefore, the correct choice is 2.

What type of chemical reaction is represented by the equation 2H₂ + O₂ → 2H₂O?

• Synthesis reaction

• Single displacement reaction

• Combustion reaction

• Decomposition reaction

Answer explanation

The reaction 2H₂ + O₂ → 2H₂O is a synthesis reaction, where two or more substances combine to form a single compound.

The chemical equation AB + CD → AD + CB represents which type of reaction?

• Combustion reaction

• Double displacement reaction

• Decomposition reaction

• Single displacement reaction

Answer explanation

The reaction AB + CD → AD + CB is a double displacement reaction because the cations and anions of the reactants exchange places to form new compounds.

What is the process called when an acid and a base react to form water and a salt?

• Combustion reaction

• Oxidation reaction

• Photosynthesis reaction

• Acid-Base Neutralization reaction

Answer explanation

The reaction between an acid and a base to produce water and a salt is known as Acid-Base Neutralization reaction.

Identify the type of reaction for the following chemical equation: CH₄ + 2O₂ → CO₂ + 2H₂O.

• Synthesis reaction

• Decomposition reaction

• Combustion reaction

• Single displacement reaction

Answer explanation

The equation CH₄ + 2O₂ → CO₂ + 2H₂O represents a combustion reaction, where methane (CH₄) reacts with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O).

What does the pH scale measure?

• acidity or basicity

• density

• weight

• temperature

Answer explanation

The pH scale is used to measure acidity or basicity. It helps determine the level of acidity or alkalinity in a substance.