Physical Science A Final Exam.-Practice

Which chemical equation is balanced?

• Na + 2Cl₂ → 2NaCl

• 2Na + Cl₂ → 2NaCl

• Na + Cl₂ → NaCl

• 2Na + 2Cl₂ → 2NaCl

What happens to the bonds of the REACTANTS in a chemical reaction?

• bonds remain unchanged

• bonds are broken and formed

• bonds are broken

• bonds are formed

What separates reactants and products in a chemical equation?

• a plus sign

• an equals sign

• a minus sign

• an arrow

In the following reaction, what are the reactants?
KOH + HCl → KCl + H₂O

• KOH only

• KCl and H₂O

•  

  KOH and HCl

• HCl and KCl

What is the missing coefficient in the following chemical equation?
_?_NO + O₂ → 2NO₂

• 0

• 1

• 2

• 4

Which of the following indicates a chemical reaction occurred?

• There is an unexpected color change.

• A phase change occurs.

• A change occurred quickly.

• Coefficients and subscripts are used.

Which of the following may be reactants and products in a chemical reaction?

• compounds

• elements and compounds

• elements

• exactly the same compounds

Which chemical equation correctly represents the balanced reaction in which carbon combines with oxygen and forms carbon dioxide?

• C₂ + 2O → C₂O₂

• C + O₂ → CO₂

• C₂ + O₂ → 2CO₂

• 2C + O → C₂O

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

• single-replacement

• decomposition

• double-replacement

• synthesis

Which of the following is an example of a synthesis reaction?

• H₂O → H₂ + O₂

• 2NO + O₂ → 2NO₂

• CH₄ + 2O₂ → CO₂ + 2H₂O

• NaOH + HCl → NaCl + H₂O