Go to the Quizzes Page Balancing Chemical Equations 0% 2 Created by AbuBakrShalabi Click "Watch Now" to watch the video. Then, answer the following questions: Please write your name and email to receive your certificate. 1 / 20 Which of the following equations is balanced? 2Na + 2Cl2 →  2NaCl H2 + O2 →  H2O C3H8 + 5O2 →  3CO2 + 4H2O Fe + 2HCl →  FeCl2 + H 2 / 20 When balancing an equation, you can change the subscripts in the chemical formulas. True False 3 / 20 When balancing the equation Fe + S →  FeS, what coefficient is needed in front of FeS? 1 It cannot be balanced. 3 2 4 / 20 When balancing an equation, you can: Change the coefficients in front of the formulas None of the above Change the chemical formulas of the reactants and products Add or remove atoms from the equation 5 / 20 What are the missing coefficients for the chemical equation below? P + O2 →  P2O5 2 , 5 , 4 1 , 3 , 4 4 , 5 , 2 2 , 2 , 5 6 / 20 What are the missing coefficients for the chemical equation below? Ag2O → Ag + O2 2 , 4 , 1 2 , 2 , 2 5 , 4 , 2 1 , 2 , 3 7 / 20 What is the coefficient needed in front of O2 to balance the following equation? CH4 + O2 →   CO2 + 2H2O 4 1 2 3 8 / 20 In a balanced equation, the total number of atoms of each element must be the same on both sides of the reaction arrow. False True 9 / 20 What is the balanced equation for the reaction between methane (CH4) and oxygen (O2) to produce carbon dioxide (CO2) and water (H2O)? CH4 + 2O2 → CO2 + 2H2O CH4 + 2O2 → 2CO2 + H2O CH4 + O2 → CO2 + H2O CH4 + O2 → CO2 + 2H2O 10 / 20 Why is it important to balance a chemical equation? To calculate the rate of reaction To identify the reactants and products To represent the Law of Conservation of Mass To make the equation look neat 11 / 20 In a closed system undergoing a chemical reaction, the total mass of the reactants must be: Less than the total mass of the products. Equal to the total mass of the products. Unrelated to the total mass of the products. Greater than the total mass of the products. 12 / 20 What is the Law of Conservation of Mass? Energy can be neither created nor destroyed. The total charge of a system must remain constant. Matter can be neither created nor destroyed in a chemical reaction. The total energy absorbed and released from a chemical reaction varies. 13 / 20 In the balanced equation N₂ + 3H₂ → 2NH₃, how many atoms of hydrogen (H) are on the reactant side? 4 2 3 6 14 / 20 In the unbalanced equation: Fe + O2 → FeO3 how many Fe atoms are on the reactant side? There is no Fe in the equation 2 1 It depends on the amount of Fe used 15 / 20 In the balanced equation 2H₂ + O₂ → 2H₂O, what is the coefficient of hydrogen (H) on the product side? 3 4 1 2 16 / 20 A chemical reaction happens when ___________. existing bonds break and the atoms rearrange to form new bonds new bonds are formed to create complex compounds new atoms are created in the products existing atoms in the reactants are destroyed 17 / 20 If 5 grams of magnesium (Mg) react with oxygen (O₂) to form magnesium oxide (MgO), the total mass of the magnesium oxide produced will be: Less than 5 grams. More than 5 grams. Exactly 5 grams. Impossible to determine without knowing the amount of oxygen used. 18 / 20 What does balancing a chemical equation mean? Replacing elements with different ones Changing the names of the reactants and products Making sure the number of atoms of each element is the same on both sides of the reaction arrow Adding heat to a reaction 19 / 20 Which statement best describes the law of conservation of energy? Energy can't be transferred between the system and the surroundings. The total energy absorbed and released from a chemical reaction varies. The amount of energy released by a system must be more than that absorbed by the surrounding. The total energy absorbed and released from a chemical reaction stays the same. 20 / 20 What is the coefficient in a balanced chemical equation? A small number written behind a chemical formula An element on the right side of the equation An element on the left side of the equation A large number written in front of a chemical formula Your score is 0% Restart quiz Go to the Quizzes Page