4, Assign oxidation states for the two elements in the compound OF2. Explain the rules that you use.
5. For each of the following oxidation-reduction reactions of metals and nonmetals, identify the element that is oxidized and the element that is being reduced.
a) 4Fe(s) + 3O2(g) --> 2Fe2O3
b)Zn(s) + 2AgNO3(aq) -->Zn(NO3)2 (aq) + 2Ag(s)
c)2K(s) + Cl2(g) -->2KCl(s)
d)2Ca(s) + O2(g) --> 2CaO(s)
a)Fe oxidized ,O2 Reduced b)Zn ,Ag c)K , Cl2 d)Ca , O2 oxidized and reduced respectively.
4. To assign oxidation states for the elements in the compound OF2, we use the following rules:
a) In a neutral compound, the sum of the oxidation states of all the individual atoms is 0.
b) Oxygen usually has an oxidation state of -2, except in peroxides (such as H2O2) where it is -1.
c) Fluorine usually has an oxidation state of -1 in compounds.
d) Since the compound OF2 is neutral and there is only one fluorine atom, its oxidation state is -1.
To determine the oxidation state of oxygen, we substitute the known values into the equation:
(oxidation state of oxygen) + 2 * (oxidation state of fluorine) = 0
(oxidation state of oxygen) + 2 * (-1) = 0
(oxidation state of oxygen) - 2 = 0
(oxidation state of oxygen) = +2
Therefore, the oxidation state of oxygen in OF2 is +2.
5. To identify the element that is oxidized and the element that is being reduced in each of the oxidation-reduction reactions involving metals and nonmetals, we need to compare the oxidation states of the elements before and after the reaction.
a) 4Fe(s) + 3O2(g) --> 2Fe2O3
In Fe2O3, iron (Fe) has an oxidation state of +3, which is higher than its initial oxidation state of 0 in Fe(s). This indicates that iron is being oxidized.
Oxygen (O) has an oxidation state of -2 in both O2(g) and Fe2O3. Therefore, oxygen is not being oxidized or reduced.
b) Zn(s) + 2AgNO3(aq) --> Zn(NO3)2(aq) + 2Ag(s)
In Zn(NO3)2, zinc (Zn) has an oxidation state of +2, which is higher than its initial oxidation state of 0 in Zn(s). This indicates that zinc is being oxidized.
Silver (Ag) has an oxidation state of 0 in both AgNO3(aq) and Ag(s). Therefore, silver is not being oxidized or reduced.
c) 2K(s) + Cl2(g) --> 2KCl(s)
In KCl, potassium (K) has an oxidation state of +1, which is lower than its initial oxidation state of 0 in K(s). This indicates that potassium is being reduced.
Chlorine (Cl) has an oxidation state of 0 in Cl2(g) and -1 in KCl. Therefore, chlorine is being reduced.
d) 2Ca(s) + O2(g) --> 2CaO(s)
In CaO, calcium (Ca) has an oxidation state of +2, which is higher than its initial oxidation state of 0 in Ca(s). This indicates that calcium is being oxidized.
Oxygen (O) has an oxidation state of -2 in both O2(g) and CaO. Therefore, oxygen is not being oxidized or reduced.