Chemistry B: Oxidation Reduction
The charge of a potassium (K) ion is
+1
The charge of a boron (B) ion is
+3
What are the oxidation numbers of the atoms in this reaction?Check all that apply. CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
- -4 for C in CH4 - +4 for C in CO2 - +1 for H in both CH4 and H2O
What are the oxidation numbers of the atoms in this reaction?Check all that apply. Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
- 0 for Mg(s) and H in H2 - +1 for H in HCl - -1 for Cl in HCl - +2 for Mg in MgCl2
Which reactions are oxidation-reduction reactions? Check all that apply.
- 2C3H6(g) + 9O2(g) → 6CO2(g) + 6H2O(g) - Fe2O3(s) + 3CO(g) → 2Fe(l) + 3CO2(g)
Assign an oxidation number to each element in the reaction. CO(g) + 2H2(g) → CH3OH(g)
- In CO, the oxidation number of C is +2, , and that of O is -2. - In H2, the oxidation number of H is 0. - In CH3OH, the oxidation number of C is -2, , that of O is-2, and that of H is +1.
Assign an oxidation number to each element in the reaction. CaF2(s) + H2SO4(aq) → CaSO4(aq) + 2HF(g)
- In CaF2, the oxidation number of Ca is +2, , and that of F is -1. - In H2SO4, the oxidation number of H is +1, that of S is +6, and that of O is -2. - In CaSO4, the oxidation number of Ca is +2, that of S is +6, and that of O is -2. - In HF, the oxidation number of H is +1, , and that of F is -1.
Describe the redox reaction. Check all that apply. 2Na(s) + Cl2(g) → 2NaCl(s)
- Sodium atoms are oxidized. - Sodium transfers electrons to chlorine.
The charge of a bromine (Br) ion is
-1
The charge of an iodine (I) ion is
-1
The charge of a sulfur (S) ion is
-2
Sodium chloride is an ionic compound. The reaction below shows how sodium chloride forms from sodium and chlorine. Which statements describe this reaction? Check all that apply. 2Na(s) + Cl2(g) → 2NaCl(s)
-Each sodium atom loses one electron. -The charge of the chloride ion in NaCl is -1.
Describe the redox reaction. Check all that apply. 2Al(s) + 3ZnCl₂(g) → 3Zn(s) + 2AlCl₃(aq)
-Zinc is reduced. -The oxidation number of chlorine does not change. -Aluminum is oxidized.
What is oxidized and what is reduced in this reaction?Cu(s) + 2AgNO3(aq) → Cu(NO3)2(aq) + 2Ag(s)
Ag is reduced and Cu is oxidized.
In the redox reaction below, which is the reducing agent? MnO2 (s) + 4H+(aq) + 2Cl (aq) Mn2+(aq) + 2H2O(l) + Cl2(g)
CI-
Given the reaction below, which is the reduced substance? Mg + Cl2 Mg2+ + 2Cl
CI2
Which of these reactions are redox reactions? Check all that apply.
Cd + HCl → CdCl2 + H2 2ZnS + 3O2 → 2ZnO + 2SO2 CH4 + 2O2 → CO2 + 2H2O
Which best describes the oxidizing agent in this reaction? Cl2(aq) + 2Br(aq) 2Cl(aq) + Br2(aq)
Chlorine (Cl) is the oxidizing agent because it gains an electron.
Cu2+ + e− → Cu+
Cu2+ is reduced.
Fe → Fe3+ + 3e−
Fe is oxidized.
Which of the following is an oxidation-reduction reaction?
Fe2O3 + 3CO → 2Fe + 3CO2
F + e− → F−
F− is reduced.
2H+ + 2e− → H2
H+ is reduced.
The presence of which reactant is the best indicator of an oxidation-reduction reaction?
H2
Given the reaction below, which is the oxidized substance? Mg + Cl2→ Mg2+ + 2Cl
Mg
What is oxidized and what is reduced in this reaction?N2H4(l) + 2H2O2(l) → N2(g) + 4H2O(g)
N is oxidized and O is reduced.
Which answer best describes what is happening in the following reaction? 2C8H18 + 25O2→ 16CO2 + 18H2O
This is a redox reaction in which octane (C8H18) is oxidized.
Which type of reaction occurs in the following? 2HgO(s) 2Hg(l) + O2(g)
a decomposition reaction in which a metal is reduced
oxidation number
a number that indicates how many electrons an atom has gained, lost, or shared to form a chemical bond with one or more atoms; in a neutral compound, the sum of oxidation numbers is zero
oxidation-reduction reaction
a reaction in which electrons are transferred from one substance to another substance
Which identifies an oxidation-reduction reaction?
a reaction in which oxidation numbers change
A fluorine atom (F) will
gain 1 electron
A lithium atom (Li) will
lose 1 electron
A calcium atom (Ca) will
lose 2 electrons
An aluminum atom (Al) will
lose 3 electrons
2l− → l2 + 2e−
l− is oxidized.
An argon atom (Ar) will
not form an ion
The loss of electrons is called
oxidation
OIL RIG
oxidation is loss, reduction is gain
The gain of electrons is called
reduction
reduction
the gain of one or more electrons
Which of the following is a simple definition of oxidation?
the loss of electrons
Oxidation
the loss of one or more electrons
reducing agent
the substance that is oxidized; the substance that produces reduction in another substance
oxidizing agent
the substance that is reduced; a substance that produces oxidation in another substance