Go to the Quizzes Page Balancing Chemical Equations 0% 3 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 When balancing an equation, you can: Add or remove atoms from the equation Change the coefficients in front of the formulas Change the chemical formulas of the reactants and products None of the above 2 / 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 3 / 20 Why is it important to balance a chemical equation? To calculate the rate of reaction To make the equation look neat To identify the reactants and products To represent the Law of Conservation of Mass 4 / 20 What are the missing coefficients for the chemical equation below? P + O2 → P2O5 2 , 5 , 4 2 , 2 , 5 1 , 3 , 4 4 , 5 , 2 5 / 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 6 / 20 Which statement best describes the law of conservation of energy? The total energy absorbed and released from a chemical reaction varies. Energy can't be transferred between the system and the surroundings. 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. 7 / 20 When balancing the equation Fe + S → FeS, what coefficient is needed in front of FeS? 3 1 2 It cannot be balanced. 8 / 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. 9 / 20 In the balanced equation N₂ + 3H₂ → 2NH₃, how many atoms of hydrogen (H) are on the reactant side? 3 2 4 6 10 / 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 11 / 20 What are the missing coefficients for the chemical equation below? Ag2O → Ag + O2 5 , 4 , 2 2 , 4 , 1 1 , 2 , 3 2 , 2 , 2 12 / 20 What is the Law of Conservation of Mass? The total charge of a system must remain constant. Energy can be neither created nor destroyed. The total energy absorbed and released from a chemical reaction varies. Matter can be neither created nor destroyed in a chemical reaction. 13 / 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 14 / 20 Which of the following equations is balanced? 2Na + 2Cl2 → 2NaCl H2 + O2 → H2O C3H8 + 5O2 → 3CO2 + 4H2O Fe + 2HCl → FeCl2 + H 15 / 20 What is the coefficient needed in front of O2 to balance the following equation? CH4 + O2 → CO2 + 2H2O 2 1 4 3 16 / 20 When balancing an equation, you can change the subscripts in the chemical formulas. True False 17 / 20 What is the coefficient in a balanced chemical equation? 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 A small number written behind a chemical formula 18 / 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. Greater than the total mass of the products. Unrelated to the total mass of the products. Equal to the total mass of the products. 19 / 20 A chemical reaction happens when ___________. new bonds are formed to create complex compounds existing bonds break and the atoms rearrange to form new bonds new atoms are created in the products existing atoms in the reactants are destroyed 20 / 20 In the balanced equation 2H₂ + O₂ → 2H₂O, what is the coefficient of hydrogen (H) on the product side? 3 2 1 4 Your score is 0% Restart quiz Go to the Quizzes Page