Redox Reactions
What is a redox reaction?
A redox reaction involves the transfer of electrons between two species
What is the first step in balancing a redox reaction in acidic solution?
Assign oxidation numbers
What is oxidation?
Oxidation is the process in which an atom, ion, or molecule loses electrons.
True or false:
Oxidation numbers are always small whole numbers
False
"Oxidation numbers are generally small whole numbers, but may be fractional"
What is the definition of an ionic bond?
An ionic bond is a chemical bond formed between two ions with opposite charges, typically between a metal and a non-metal.
What are the two components of a redox reaction?
The two components of a redox reaction are oxidation (the loss of electrons) and reduction (the gain of electrons)
When balancing a redox reaction, why do you add electrons to the half-reactions?
Electrons are added to balance the charges (so that the number of electrons lost in oxidation equals the number gained in reduction).
Which element in a redox reaction is gaining electrons?
The element that is gaining electrons is being reduced.
What is the oxidation number of chlorine in NaCl?
The oxidation number of chlorine in NaCl -1
How do you determine the empirical formula of a compound from its molecular formula?
The empirical formula is the simplest whole-number ratio of elements in a compound, which can be determined by dividing the molar ratio of each element in the molecular formula by the greatest common factor.
In the reaction between zinc and copper sulfate, which substance is reduced?
In the reaction between zinc and copper sulfate, zinc (Zn) is oxidized and copper (Cu²⁺) is reduced.
How do you balance oxygen atoms in a redox reaction?
Oxygen atoms are balanced by adding H2O to the side that needs oxygen
What is the definition of a reducing agent?
A reducing agent is a substance that donates electrons to another substance, thereby reducing it.
What is the oxidation number of sulfur in H2SO4
The oxidation number of sulfur in H2SO4 is +6
How do you calculate the pH of a solution from its hydrogen ion concentration?
The pH of a solution is calculated by the formula:
pH=−log[H+]
What happens to the oxidation state of an atom during reduction?
During reduction, the oxidation state of an atom decreases (it gains electrons).
What’s the role of the electrons when balancing redox reactions in basic solutions?
In basic solutions, after balancing the reaction in acidic solution, OH- is added to both sides of the equation to neutralize H+ ions and convert the reaction into basic conditions.
When an element is oxidized, what happens to its charge?
The oxidation number of the element increases as it loses electrons.
What is the rule for assigning oxidation numbers to elements in their elemental form?
The rule is that the oxidation number of an element in its elemental form is 0 (e.g., in O2, N2).
What is the ideal gas law equation?
The ideal gas law equation is PV=nRT
P = pressure
V = volume
n = moles of gas
R = ideal gas constant
T = temperature in Kelvin.
What is the role of a half-reaction in a redox process?
Half-reactions represent either the oxidation or reduction half of the full redox process, showing the flow of electrons.
Balance the following reaction in acidic solution:
Cr2O72- + H2O -->Cr3++ OH-
Ensure the same number of atoms and charges are balanced on both sides.
Cr2O72- + 14H+ +6e- --> 2Cr3++7H2O
Which of the following is the strongest oxidizing agent? Cl2. Fe2+, Na, Cu2+
Cl2 (chlorine) is the strongest oxidizing agent among the options, as it readily gains electrons.
In the compound KMnO4, what is the oxidation number of manganese?
The oxidation number of manganese (Mn) in KMnO4 is +7.
What does electrochemistry study?
The study of the interconversion of electrical and chemical energy.
The chemical reactions involve electron transfer