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 In the unbalanced equation: Fe + O2 → FeO3 how many Fe atoms are on the reactant side? There is no Fe in the equation It depends on the amount of Fe used 1 2 2 / 20 Which of the following equations is balanced? H2 + O2 →  H2O Fe + 2HCl →  FeCl2 + H 2Na + 2Cl2 →  2NaCl C3H8 + 5O2 →  3CO2 + 4H2O 3 / 20 A chemical reaction happens when ___________. 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 existing atoms in the reactants are destroyed 4 / 20 When balancing the equation Fe + S →  FeS, what coefficient is needed in front of FeS? 1 It cannot be balanced. 3 2 5 / 20 Which statement best describes the law of conservation of energy? Energy can't be transferred between the system and the surroundings. The total energy absorbed and released from a chemical reaction varies. 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. 6 / 20 In the balanced equation 2H₂ + O₂ → 2H₂O, what is the coefficient of hydrogen (H) on the product side? 1 4 3 2 7 / 20 What are the missing coefficients for the chemical equation below? Ag2O → Ag + O2 2 , 2 , 2 2 , 4 , 1 1 , 2 , 3 5 , 4 , 2 8 / 20 What does balancing a chemical equation mean? Replacing elements with different ones Adding heat to a reaction 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 9 / 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 → 2CO2 + H2O CH4 + O2 → CO2 + 2H2O CH4 + 2O2 → CO2 + 2H2O CH4 + O2 → CO2 + H2O 10 / 20 What is the Law of Conservation of Mass? 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. Energy can be neither created nor destroyed. 11 / 20 In a closed system undergoing a chemical reaction, the total mass of the reactants must be: Greater than the total mass of the products. Unrelated to the total mass of the products. Less than the total mass of the products. Equal to the total mass of the products. 12 / 20 What are the missing coefficients for the chemical equation below? P + O2 →  P2O5 2 , 5 , 4 4 , 5 , 2 1 , 3 , 4 2 , 2 , 5 13 / 20 In the balanced equation N₂ + 3H₂ → 2NH₃, how many atoms of hydrogen (H) are on the reactant side? 6 4 2 3 14 / 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 An element on the right side of the equation A large number written in front of a chemical formula 15 / 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 16 / 20 When balancing an equation, you can change the subscripts in the chemical formulas. False True 17 / 20 Why is it important to balance a chemical equation? To represent the Law of Conservation of Mass To identify the reactants and products To make the equation look neat To calculate the rate of reaction 18 / 20 When balancing an equation, you can: Change the coefficients in front of the formulas Add or remove atoms from the equation Change the chemical formulas of the reactants and products None of the above 19 / 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. 20 / 20 What is the coefficient needed in front of O2 to balance the following equation? CH4 + O2 →   CO2 + 2H2O 3 4 1 2 Your score is 0% Restart quiz Go to the Quizzes Page