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