Go to the Quizzes Page Balancing Chemical Equations 0% 315 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 A chemical reaction happens when ___________. new bonds are formed to create complex compounds existing atoms in the reactants are destroyed new atoms are created in the products existing bonds break and the atoms rearrange to form new bonds 2 / 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 3 / 20 What is the Law of Conservation of Mass? Matter can be neither created nor destroyed in a chemical reaction. The total charge of a system must remain constant. The total energy absorbed and released from a chemical reaction varies. Energy can be neither created nor destroyed. 4 / 20 In a closed system undergoing a chemical reaction, the total mass of the reactants must be: Unrelated to the total mass of the products. Equal to the total mass of the products. Greater than the total mass of the products. Less than the total mass of the products. 5 / 20 Why is it important to balance a chemical equation? To calculate the rate of reaction To represent the Law of Conservation of Mass To identify the reactants and products To make the equation look neat 6 / 20 What are the missing coefficients for the chemical equation below? P + O2 →  P2O5 4 , 5 , 2 2 , 5 , 4 1 , 3 , 4 2 , 2 , 5 7 / 20 What are the missing coefficients for the chemical equation below? Ag2O → Ag + O2 1 , 2 , 3 2 , 4 , 1 2 , 2 , 2 5 , 4 , 2 8 / 20 In the unbalanced equation: Fe + O2 → FeO3 how many Fe atoms are on the reactant side? 1 It depends on the amount of Fe used 2 There is no Fe in the equation 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 + O2 → CO2 + H2O CH4 + 2O2 → 2CO2 + H2O CH4 + O2 → CO2 + 2H2O CH4 + 2O2 → CO2 + 2H2O 10 / 20 When balancing the equation Fe + S →  FeS, what coefficient is needed in front of FeS? 1 It cannot be balanced. 2 3 11 / 20 When balancing an equation, you can: None of the above Change the chemical formulas of the reactants and products Change the coefficients in front of the formulas Add or remove atoms from the equation 12 / 20 When balancing an equation, you can change the subscripts in the chemical formulas. True False 13 / 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. 14 / 20 In the balanced equation N₂ + 3H₂ → 2NH₃, how many atoms of hydrogen (H) are on the reactant side? 4 2 3 6 15 / 20 Which of the following equations is balanced? 2Na + 2Cl2 →  2NaCl C3H8 + 5O2 →  3CO2 + 4H2O H2 + O2 →  H2O Fe + 2HCl →  FeCl2 + H 16 / 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. Impossible to determine without knowing the amount of oxygen used. Exactly 5 grams. More than 5 grams. 17 / 20 What is the coefficient in a balanced chemical equation? An element on the left side of the equation An element on the right side of the equation A large number written in front of a chemical formula A small number written behind a chemical formula 18 / 20 In the balanced equation 2H₂ + O₂ → 2H₂O, what is the coefficient of hydrogen (H) on the product side? 3 1 2 4 19 / 20 What is the coefficient needed in front of O2 to balance the following equation? CH4 + O2 →   CO2 + 2H2O 3 1 4 2 20 / 20 In a balanced equation, the total number of atoms of each element must be the same on both sides of the reaction arrow. True False Your score is 0% Restart quiz Go to the Quizzes Page