Which reaction will occur if each substance is in its standard state?
(A) Ni2+ will oxidize Sn2+ to give Sn4+
(B) Sn4+ will oxidize Br– to give Br2
(C) Br2 will oxidize Ni(s) to give Ni2+
(D) Ni2+ will oxidize Br2 to give Br–
I don't know how to do these except to look up the reduction potentials in a table and compare. What do you havae the text or your notes, or what are you covering, that will answer these?
To determine which reaction will occur if each substance is in its standard state, we need to compare the standard reduction potentials of the different reactions. The reaction with the highest positive reduction potential will occur.
Here are the standard reduction potentials for the involved species:
Ni2+ + 2e- -> Ni: -0.25 V
Sn2+ + 2e- -> Sn: -0.14 V
Br2 + 2e- -> 2Br-: +1.07 V
Let's analyze each option:
(A) Ni2+ will oxidize Sn2+ to give Sn4+:
To calculate the standard potential for this reaction, we need to sum the reduction potentials for the oxidation (Ni2+ -> Ni) and reduction (Sn2+ -> Sn4+). The total potential would be -0.25 V + (-0.14 V) = -0.39 V, which is negative. Thus, this reaction is not spontaneous, and option (A) is incorrect.
(B) Sn4+ will oxidize Br– to give Br2:
The standard potential for this reaction would be the reduction potential of Br2 (+1.07 V), as there is no need to combine it with another half-reaction. It is the highest value among the given species. Therefore, option (B) suggests a spontaneous reaction.
(C) Br2 will oxidize Ni(s) to give Ni2+:
The standard potential for this reaction would be the reduction potential of Br2 (+1.07 V) and the oxidation of Ni(s) to Ni2+ (-0.25 V). The total potential would be +1.07 V + (-0.25 V) = +0.82 V, which is positive. Thus, this reaction may occur spontaneously, and option (C) could be valid.
(D) Ni2+ will oxidize Br2 to give Br–:
To determine the standard potential for this reaction, we must sum the reduction potentials for the oxidation of Ni2+ to Ni (+0.25 V) and the reduction of Br2 to Br- (+1.07 V). The total potential would be +0.25 V + (+1.07 V) = +1.32 V, which is positive. Hence, this reaction could be spontaneous, and option (D) might be correct.
In conclusion, option (B) and option (D) both suggest reactions that could occur spontaneously, but we need more information to determine which one is more likely to occur. Consider factors like concentration, temperature, and additional potential energy calculations if available.