A chemical reaction in which electrons are transferred from one substance (the reducing agent, which is oxidized) to another (the oxidizing agent, which is reduced).
One thing loses electrons (oxidized), another gains them (reduced).
Showing a random 20 of 50 problems.
Example 1
easy
In Cl2+2e−→2Cl−, is chlorine oxidized or reduced?
Example 2
easy
What is the oxidation number of a free element such as Na metal?
Example 3
easy
In a redox reaction, the oxidizing agent is the species that does what to electrons?
Example 4
medium
Find the oxidation state of Mn in KMnO4.
Example 5
medium
Is CaCO3→CaO+CO2 a redox reaction?
Example 6
hard
In a galvanic cell with overall reaction Zn+Cu2+→Zn2++Cu, identify the species reduced and the cathode material.
Example 7
medium
In 2Fe3++Sn2+→2Fe2++Sn4+, how many electrons does tin lose?
Example 8
medium
What is the oxidation number of nitrogen in HNO3?
Example 9
medium
In Cu+2Ag+→Cu2++2Ag, how many electrons are transferred per Cu atom?
Example 10
hard
In NaH, what is the oxidation state of hydrogen?
Example 11
medium
Determine whether the following reaction is a redox reaction: HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l). Justify your answer.
Example 12
easy
Define a redox reaction and explain the relationship between oxidation and reduction.
Example 13
easy
In 2Na+Cl2→2NaCl, which species is the reducing agent?
Example 14
medium
Is the disproportionation Cl2→Cl−+ClO− a redox reaction?
Example 15
easy
What is the oxidation number of oxygen in most compounds such as H2O?
Example 16
medium
In MnO4−→Mn2+, what is the change in oxidation number of Mn?
Example 17
easy
OIL RIG: what does 'OIL' stand for?
Example 18
medium
Balance the reduction half-reaction O2→O2− for the oxide ion.
Example 19
medium
At which electrode does oxidation occur in a galvanic cell?
Example 20
challenge
In 3Cu+8HNO3→3Cu(NO3)2+2NO+4H2O, how many electrons are transferred total?