4.3 Quest Review Chemical Reactions

In a chemical reation the substances that are created are called?

• Reactants

• Products

• Coefficients

• Elements

What is the purpose of balancing a chemical equation?

• To make the equation easier to read

• To increase the speed of the reaction

• To ensure the law of conservation of mass is obeyed

• To change the products of the reaction

In the balanced chemical equation:
2Na + Cl₂ → 2NaCl, how many sodium atoms are involved in the reaction?

• 1

• 2

• 4

• 3

Which of the following is the correct formula for a compound formed between calcium and carbonate?

• Ca(CO₃)

• Ca₂(CO₃)₂

• CaC₂

• C₃(CO₂)

2H₂ + O₂ → 2H₂O, how many oxygen molecules are there on the reactant side of the equation?

• 1

• 2

• 3

• 0

2H₂ + O₂ → 2H₂O, how many water molecules are there on the product side of the equation?

• 1

• 2

• 3

• 4

2H₂ + O₂ → 2H₂O, how many hydrogen atoms are on each side of the equation?

• 1

• 2

• 3

• 4

Which of the following is true about coefficients in a chemical equation?

• They are the same as subscripts in the formulas.

• They are used to change the chemical structure of the reactants.

• They are placed in front of formulas to balance the equation.

• They represent the atomic mass of the compound in the reaction

Which of the following correctly balances the equation for the reaction of

CH₄ + O₂ --> CO₂ + H₂O ?

• CH₄ + O₂ → CO₂ + H₂O

• CH₄ + 2O₂ → CO₂ + 2H₂O

• CH₄ + 2O₂ → 2CO₂ + 2H₂O

• CH₄ + O₂ → 2CO₂ + H₂O

Which of the following formulas is correctly balanced?

• 2H₂ + O₂ → H₂O

• 2Na + Cl₂ → NaCl

• 2H₂O → 2H₂ + O₂

• 2C₆H₆ + 15O₂ → 12CO₂ + 6H₂O