36 Questions
According to the oxidation number method, what must be equal in a balanced redox equation?
The total increase in oxidation numbers
Which atoms or ions are oxidized and reduced in the given redox equation? Cu + HNO3 → Cu(NO3)2 + NO2 + H2O
Cu is oxidized, N is reduced
What is the oxidation number of copper in the given redox equation? Cu + HNO3 → Cu(NO3)2 + NO2 + H2O
+2
Which of the following is true about the balanced redox equation?
The number of atoms of each element is equal on both sides of the equation
When balancing equations in an acidic solution, what can be added to either side of the equation?
Hydrogen ions (H+) or water molecules
When balancing equations in a basic solution, what can be added to either side of the equation?
Hydrogen ions (H+) or water molecules
What is a chemical unit involved in a process called?
A species
Which of the following is true about the oxidation and reduction processes in a redox reaction?
The oxidation number of the oxidized species increases
What is the change in oxidation number for nitrogen in the reaction Cu + 2HNO3 → Cu(NO3)2 + 2NO2 + H2O?
+1
In which solution can hydroxide ions (OH-) be added to balance a redox equation?
Basic solution
What is the balanced net ionic equation for the reaction ClO4–(aq) + Br–(aq) → Cl–(aq) + Br2(g) in acidic solution?
ClO4–(aq) + 8Br–(aq) → Cl–(aq) + 4Br2(g)
Match the following terms with their definitions:
Oxidation-number method = A method used to balance redox equations by ensuring that the number of electrons transferred from atoms equals the number of electrons accepted by other atoms Net ionic equation = An ionic equation that includes only the particles that participate in the reaction Oxidized atom = An atom that has lost electrons in a redox reaction Reduced atom = An atom that has gained electrons in a redox reaction
Match the following equations with the corresponding changes in oxidation numbers:
Cu + HNO3 → Cu(NO3)2 + NO2 + H2O = The oxidation number of nitrogen decreases from +5 to +4 Cu + 2HNO3 → Cu(NO3)2 + 2NO2 + H2O = The oxidation number of nitrogen decreases from +5 to +4
Match the following statements with the corresponding redox reactions:
Cu is oxidized. N is reduced. H does not change. O does not change. = $Cu + 2HNO3 → Cu(NO3)2 + 2NO2 + H2O$
Match the following terms with their correct descriptions in a redox reaction:
Oxidation = The process in which a species loses electrons Reduction = The process in which a species gains electrons Half-reaction = One of the two parts of a redox reaction, either the oxidation or the reduction Species = Any kind of chemical unit involved in a process, such as a molecule, an atom, or an ion
Match the following ions with their correct role in balancing a redox equation:
$H^+$ = Can be used to balance the charge in an acid solution $OH^-$ = Cannot be added to balance a redox equation in an acidic solution $H^+$ or $H_2O$ = Can be added to either side of the equation when balancing equations in an acidic solution $H^+$ or $H_2O$ or $OH^-$ = Can be added to either side of the equation when balancing equations in a basic solution
Match the following elements with their correct oxidation states in the given redox equations:
Copper (Cu) = $+1$ in $Cu(NO_3)_2$ and $+2$ in $Cu$ Manganese (Mn) = $+7$ in $MnO_4^-$ and $+2$ in $Mn$ Tin (Sn) = $+2$ in $SnCl_2$ and $+4$ in $SnCl_4$ Hydrogen (H) = $+1$ in $H^+$ and $0$ in $H_2O$
Match the following terms with their correct definitions in the context of balancing redox equations:
Half-reactions = The balanced oxidation and reduction equations in a redox reaction Spectator ions = Ions that do not participate in the redox reaction and appear the same on both sides of the equation Oxidation numbers = Positive or negative numbers assigned to atoms or ions to indicate their degree of oxidation or reduction Balanced equation = An equation in which the number of atoms of each element is equal on both sides and no subscripts have been changed
Match the following redox equations with the correct changes in oxidation numbers:
Cu + 2HNO3 → Cu(NO3)2 + 2NO2 + H2O = $\Delta$N = -1, $\Delta$Cu = +2 ClO4–(aq) + 8Br–(aq) + 8H+ (aq) → Cl–(aq) + 4Br2(g) + 4H2O(l) = $\Delta$Br = +1, $\Delta$Cl = -6 KMnO4(aq) + SnCl2(aq) + HCl(aq) → MnCl2(aq) + SnCl4(aq) + H2O(l) + KCl(aq) = $\Delta$Sn = +2, $\Delta$Mn = +7 Cu(s) + 4HNO3 (aq) → Cu(NO 3)2(aq) + 2NO2(g) + 2H2O(l) = $\Delta$Cu = 0, $\Delta$N = -3
Match the following redox equation terms with their definitions:
Oxidation = The process in which an atom or ion loses electrons Reduction = The process in which an atom or ion gains electrons Half-Reaction = One of the two parts of a redox reaction, either the oxidation half or the reduction half Net Ionic Equation = An equation that shows only the species that actually participate in the reaction
Match the following redox equation terms with their corresponding solutions:
Hydrogen ions (H+) = Added to the left side of the equation in an acidic solution Hydroxide ions (OH–) = Added to either side of the equation in a basic solution Water molecules = Can be added to either side of the equation in both acidic and basic solutions Spectator ions = Eliminated when balancing a redox equation using half-reactions
Match the following redox equation steps with their corresponding equations:
Assign oxidation numbers = $\Delta$Cu +2, $\Delta$N –1 Adjust coefficients = $\Delta$Br +1, $\Delta$Cl -6 Add hydrogen ions and water molecules = $\Delta$Sn +2, $\Delta$Mn +7 Balance the atoms and charges in the half-reactions = $\Delta$Cu 0, $\Delta$N -3
Quiz 1 The total increase in oxidation numbers must be greater than the total decrease in oxidation numbers in the reaction.
False
Quiz 2 Which can be added to either side of the equation when balancing equations in an acidic solution.
False
Quiz 3 Which can be added to either side of the equation when balancing equations in a basic solution.
False
Quiz 4 Which is any kind of chemical unit involved in a process.
False
True or false: Copper gains electrons and is reduced in the redox reaction Cu + 2HNO3 → Cu(NO3)2 + 2NO2 + H2O.
False
True or false: The oxidation number of bromine in ClO4–(aq) + Br–(aq) → Cl–(aq) + Br2(g) (in acidic solution) decreases from -1 to 0.
False
True or false: In the redox equation KMnO4(aq) + SnCl2(aq) + HCl(aq) → MnCl2(aq) + SnCl4(aq) + H2O(l) + KCl(aq), the MnO4– ion is reduced.
True
True or false: The balanced net ionic equation for the reaction ClO4–(aq) + Br–(aq) → Cl–(aq) + Br2(g) in acidic solution is ClO4– + 8H+ + 8Br– → Cl– + 4Br2 + 4H2O.
False
True or false: Changes in oxidation numbers are related to the transfer of electrons in a redox reaction.
True
True or false: The oxidation number of copper in the reaction Cu + HNO3 → Cu(NO3)2 + NO2 + H2O increases from 0 to +2.
True
True or false: The total increase in oxidation numbers must equal the total decrease in oxidation numbers in a balanced redox equation.
True
True or false: Changes in oxidation numbers are related to the transfer of electrons in redox reactions.
True
True or false: The oxidation-number method is used to balance redox equations.
True
True or false: The total increase in oxidation numbers must equal the total decrease in oxidation numbers in a redox reaction.
True
Test your understanding of balancing redox reactions and the relationship between changes in oxidation number and the transfer of electrons. This quiz will cover the oxidation-number method, half-reactions, and net ionic equations.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
