Determine whether each reaction is a redox reaction. For each redox reaction, identify the oxidizing agent and the reducing agent. a. 4 Li(s) + O2(g) → 2 Li2O(s) b. Mg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s)
Ch.4 - Chemical Quantities & Aqueous Reactions
Chapter 4, Problem 99
Is the following formulation of a task correct? If not, please correct it: Complete and balance each combustion reaction equation. a. S(s) + O2(g) → b. C3H6(g) + O2(g) → c. Ca(s) + O2(g) → d. C5H12S(l) + O2(g) →

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Identify the reactants and products in each combustion reaction. Combustion typically involves a substance reacting with oxygen to form oxides.
For each reaction, write the unbalanced chemical equation. For example, for reaction (a), write S(s) + O_2(g) → SO_2(g).
Balance each equation by adjusting the coefficients to ensure the same number of each type of atom on both sides of the equation. Start with the most complex molecule.
Check that the number of atoms for each element is equal on both sides of the equation. Adjust coefficients as necessary to achieve balance.
Verify that the balanced equation follows the law of conservation of mass, meaning the total mass of reactants equals the total mass of products.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Combustion Reactions
Combustion reactions are chemical processes in which a substance reacts rapidly with oxygen, producing heat and light. Typically, these reactions involve hydrocarbons or other organic compounds, resulting in products like carbon dioxide and water. Understanding the general form of combustion reactions is essential for balancing them correctly.
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Combustion Apparatus
Balancing Chemical Equations
Balancing chemical equations involves ensuring that the number of atoms for each element is the same on both sides of the equation. This is achieved by adjusting coefficients in front of the reactants and products. A balanced equation reflects the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.
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Balancing Chemical Equations
State Symbols in Chemical Reactions
State symbols indicate the physical state of the reactants and products in a chemical reaction. Common symbols include (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous solutions. These symbols provide important information about the conditions under which the reaction occurs and can influence the balancing of the equation.
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Related Practice
Textbook Question
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Textbook Question
Determine whether each reaction is a redox reaction. For each redox reaction, identify the oxidizing agent and the reducing agent. c. Pb(NO3)2(aq) + Na2SO4(aq) → PbSO4(s) + 2 NaNO3(aq) d. HBr(aq) + KOH(aq) → H2O(l) + KBr(aq)
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Textbook Question
Determine whether each reaction is a redox reaction. For each redox reaction, identify the oxidizing agent and the reducing agent. a. Al(s) + 3 Ag+(aq) → Al3+(aq) + 3 Ag(s) b. SO3(g) + H2O(l) → H2SO4(aq) c. Ba(s) + Cl2(g) → BaCl2(s) d. Mg(s) + Br2(l) → MgBr2(s)
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Textbook Question
The density of a 20.0% by mass ethylene glycol (C2H6O2) solution in water is 1.03 g/mL. Find the molarity of the solution.
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Textbook Question
Find the percent by mass of sodium chloride in a 1.35 M NaCl solution. The density of the solution is 1.05 g/mL.
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Open Question
People sometimes use sodium bicarbonate as an antacid to neutralize excess hydrochloric acid in an upset stomach. What mass of hydrochloric acid (in grams) can 2.5 g of sodium bicarbonate neutralize? (Hint: Begin by writing a balanced equation for the reaction between aqueous sodium bicarbonate and aqueous hydrochloric acid.)