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