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 What is the coefficient needed in front of O2 to balance the following equation? CH4 + O2 → CO2 + 2H2O 4 3 2 1 2 / 20 When balancing an equation, you can: Add or remove atoms from the equation Change the chemical formulas of the reactants and products None of the above Change the coefficients in front of the formulas 3 / 20 In the balanced equation N₂ + 3H₂ → 2NH₃, how many atoms of hydrogen (H) are on the reactant side? 6 2 3 4 4 / 20 Why is it important to balance a chemical equation? To make the equation look neat To calculate the rate of reaction To identify the reactants and products To represent the Law of Conservation of Mass 5 / 20 What does balancing a chemical equation mean? 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 Replacing elements with different ones Adding heat to a reaction 6 / 20 In the balanced equation 2H₂ + O₂ → 2H₂O, what is the coefficient of hydrogen (H) on the product side? 3 4 1 2 7 / 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. Less than 5 grams. Exactly 5 grams. 8 / 20 A chemical reaction happens when ___________. existing atoms in the reactants are destroyed new atoms are created in the products new bonds are formed to create complex compounds existing bonds break and the atoms rearrange to form new bonds 9 / 20 When balancing an equation, you can change the subscripts in the chemical formulas. False True 10 / 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. 11 / 20 What is the coefficient in a balanced chemical equation? A large number written in front of a chemical formula 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 12 / 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 13 / 20 When balancing the equation Fe + S → FeS, what coefficient is needed in front of FeS? It cannot be balanced. 1 3 2 14 / 20 Which of the following equations is balanced? H2 + O2 → H2O Fe + 2HCl → FeCl2 + H 2Na + 2Cl2 → 2NaCl C3H8 + 5O2 → 3CO2 + 4H2O 15 / 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. Greater than the total mass of the products. Unrelated to the total mass of the products. Less than the total mass of the products. 16 / 20 In the unbalanced equation: Fe + O2 → FeO3 how many Fe atoms are on the reactant side? It depends on the amount of Fe used 1 There is no Fe in the equation 2 17 / 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 18 / 20 What are the missing coefficients for the chemical equation below? Ag2O → Ag + O2 1 , 2 , 3 2 , 2 , 2 2 , 4 , 1 5 , 4 , 2 19 / 20 What is the Law of Conservation of Mass? The total energy absorbed and released from a chemical reaction varies. 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. 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 + O2 → CO2 + 2H2O CH4 + 2O2 → CO2 + 2H2O CH4 + 2O2 → 2CO2 + H2O CH4 + O2 → CO2 + H2O Your score is 0% Restart quiz Go to the Quizzes Page