The oxidation state numbercan aid in identifying the unknown element present in both compounds. They denote the number of electrons that are either donated, received, or shared to yield compounds.
Remember the fundamental principles governing oxidation numbers.
1. In a neutral compound, the total of all oxidation numbers is zero.
2. Chlorine, bromine, and iodine typically exhibit an oxidation number of -1(unless paired with fluorine and oxygen)
Assume the oxidation state for element Mis designated as x.
Referring to rule 2, chlorine possesses an oxidation state of -1.
Now, for the compound MCl₂ (which is neutral), the equation can be formulated as
x + (2 * -1)= 0 ⇒ x₁= +2
For MCl₃, the corresponding equation is
x + (3 * -1)= 0 ⇒ x₂= +3
This indicates that the elementhas two distinct oxidation statesin its compounds, which are +2and +3.
The identified element is iron (Fe), as it shows +2 and +3 oxidation states across these compounds.
Memorizing this is essential. Regrettably, there isn't a simpler method to tackle these oxidation states.
The final answer is iron (Fe).
Response:1816.6 joules
Clarification:refer to the attached image
(a)
Write the balanced half-reactions for the overall process:
Oxidation: Se^2- (aq) → Se
(s) + 2e-
Reduction: 2So3^2- (aq) + 3H2O (l) + 4e- →
S2O3^2- + 6OH- (aq)
(b)
Assuming E sulfite is 0.57 V, compute E selenium:
E anode = E cathode – E cell
= -0.57 – 0.35
=
-.092
