Question 1: Which of the following is a balanced chemical equation?

Answer: 2H2 + O2 -> 2H2O

Question 2: True or False: The mass of the reactants must equal the mass of the products in a chemical reaction.

Answer: True

Question 3: What is the coefficient for H2 in the balanced equation of H2 + Cl2 -> HCl?

Answer: 1

Question 4: Balance the following chemical equation: C2H4 + O2 -> CO2 + H2O.

Answer: C2H4 + 3O2 -> 2CO2 + 2H2O

Question 5: Match the following terms to their definitions:

Answer: See full answer key

Question 6: True or False: In a chemical reaction, atoms are destroyed.

Answer: False

Question 7: Explain why it's necessary to balance chemical equations.

Answer: It is necessary to balance chemical equations to comply with the law of conservation of mass, ensuring that the number of atoms for each element is the same on both sides of the equation.

Question 8: Balance the following equation using the formula: Fe + O2 -> Fe2O3. Show your working.

Answer: 4Fe + 3O2 -> 2Fe2O3

Question 9: Fill in the blank: A balanced chemical equation has equal numbers of each type of ___ on both sides.

Answer: atom

Question 10: Order the steps to balance a chemical equation: Identify unbalanced elements, Adjust coefficients, Check balance, Repeat if necessary.

Answer: See full answer key

Question 11: What is the role of a catalyst in a chemical reaction?

Answer: A catalyst speeds up a chemical reaction without being consumed in the process.

Question 12: Identify the type of reaction: 2H2 + O2 -> 2H2O.

Answer: Combination reaction

Question 13: Multiple choice: Which of the following is NOT a reason for balancing chemical equations?

Answer: To change the identity of the reactants

Question 14: Define the term 'stoichiometry' in the context of chemical reactions.

Answer: Stoichiometry is the calculation of reactants and products in chemical reactions.