Go to the Quizzes Page Balancing Chemical Equations 0% 316 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 Which of the following equations is balanced? C3H8 + 5O2 →  3CO2 + 4H2O H2 + O2 →  H2O Fe + 2HCl →  FeCl2 + H 2Na + 2Cl2 →  2NaCl 2 / 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 3 / 20 What does balancing a chemical equation mean? 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 Replacing elements with different ones Adding heat to a reaction 4 / 20 In the balanced equation N₂ + 3H₂ → 2NH₃, how many atoms of hydrogen (H) are on the reactant side? 6 4 2 3 5 / 20 What is the coefficient needed in front of O2 to balance the following equation? CH4 + O2 →   CO2 + 2H2O 3 1 4 2 6 / 20 When balancing an equation, you can change the subscripts in the chemical formulas. False True 7 / 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. 8 / 20 What are the missing coefficients for the chemical equation below? Ag2O → Ag + O2 1 , 2 , 3 2 , 4 , 1 5 , 4 , 2 2 , 2 , 2 9 / 20 Why is it important to balance a chemical equation? To calculate the rate of reaction To identify the reactants and products To make the equation look neat To represent the Law of Conservation of Mass 10 / 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 11 / 20 When balancing the equation Fe + S →  FeS, what coefficient is needed in front of FeS? 2 1 It cannot be balanced. 3 12 / 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 13 / 20 Which statement best describes the law of conservation of energy? 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. Energy can't be transferred between the system and the surroundings. The total energy absorbed and released from a chemical reaction stays the same. 14 / 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: More than 5 grams. Exactly 5 grams. Impossible to determine without knowing the amount of oxygen used. Less than 5 grams. 15 / 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 + O2 → CO2 + H2O CH4 + 2O2 → CO2 + 2H2O CH4 + 2O2 → 2CO2 + H2O 16 / 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 17 / 20 A chemical reaction happens when ___________. existing atoms in the reactants are destroyed existing bonds break and the atoms rearrange to form new bonds new bonds are formed to create complex compounds new atoms are created in the products 18 / 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. Less than the total mass of the products. Greater than the total mass of the products. 19 / 20 In the balanced equation 2H₂ + O₂ → 2H₂O, what is the coefficient of hydrogen (H) on the product side? 2 1 4 3 20 / 20 What are the missing coefficients for the chemical equation below? P + O2 →  P2O5 2 , 2 , 5 1 , 3 , 4 4 , 5 , 2 2 , 5 , 4 Your score is 0% Restart quiz Go to the Quizzes Page