Multiple Choice
What is the oxidation state of sulfur in the ion SO_4^{2-}?
35
views
6. Chemical Quantities & Aqueous Reactions
Calculate Oxidation Numbers
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
What is the oxidation number of Fe in Fe_2O_3?
A
-3
B
0
C
+2
D
+3
Verified step by step guidance1
Identify the oxidation number of oxygen in the compound. Oxygen almost always has an oxidation number of -2 in its compounds.
Write the general formula for the sum of oxidation numbers in a neutral compound: the sum of oxidation numbers of all atoms must equal zero.
Let the oxidation number of Fe be x. Since there are 2 Fe atoms, their total contribution is 2x. For oxygen, there are 3 atoms each with -2, so total is 3 \times (-2) = -6.
Set up the equation based on the sum of oxidation numbers: 2x + (-6) = 0.
Solve the equation for x: 2x = 6, so x = +3. Therefore, the oxidation number of Fe in Fe_2O_3 is +3.
Related Videos
Related Practice
Calculate Oxidation Numbers practice set
Problem sets built by lead tutorsExpert video explanations