T1.15 Which ONE of the following statements is TRUE for an oxidising agent? A) It gains electrons. B) It causes another species in the reaction to be reduced. C) Its oxidation number does not change during a chemical reaction. D) Its oxidation number increases during a chemical reaction. edu1.6 Which ONE of the following metals will reduce Cd2+(aq) to Cd(s), but will NOT reduce Mn2+(aq) to Mn(s)? A) Zn B) Ag C) Ni D) Mg
Answer (1)
Let's examine each part of the question one by one:
T1.15: Oxidising Agent
To determine which statement is true for an oxidizing agent, we must understand what an oxidizing agent does:
It gains electrons - This statement is true. An oxidizing agent gains electrons during the reaction, causing another species to lose them, and undergoes a reduction itself.
It causes another species in the reaction to be reduced - This statement is false. An oxidizing agent causes another species to be oxidized, not reduced.
Its oxidation number does not change during a chemical reaction - This statement is false. An oxidizing agent changes its oxidation number because it gains electrons.
Its oxidation number increases during a chemical reaction - This statement is false. The oxidation number of the oxidizing agent decreases because gaining electrons reduces its oxidation state.
The correct choice here is A) It gains electrons.
edu1.6: Metal Reduction of Cd2+ and Mn2+
To determine which metal can reduce Cd²⁺ to Cd but not Mn²⁺ to Mn, we look at the standard reduction potential of these ions and metals:
Zn has a more negative reduction potential compared to Cd but cannot reduce Mn due to lesser reduction potential compared to Mn.
Ag has a positive reduction potential which is not strong enough to reduce Cd or Mn.
Ni can reduce Cd but not Mn when considering their standard reduction potentials.
Mg can reduce both Cd and Mn since it has a high tendency to lose electrons due to its low reduction potential.
Thus, the metal that fits the criterion of reducing Cd²⁺ to Cd but not Mn²⁺ to Mn is C) Ni.
By understanding these concepts, we determine that the correct choices are T1.15: Option A and edu1.6: Option C .
