Elemental magnesium reacts with tungsten(II) oxide in a single displacement reaction. What is the oxidation number of the elemental magnesium?
0
+1
+2
+3
All elements in the free state have an oxidation number of zero.
To determine the oxidation number of elemental magnesium in the given reaction, we need to consider the oxidation states of the other elements involved.
In this reaction, magnesium is reacting with tungsten(II) oxide. The roman numeral in the name "tungsten(II) oxide" indicates that tungsten is in the +2 oxidation state.
Since tungsten is in the +2 oxidation state, and the overall compound is neutral, we can determine the oxidation state of oxygen by using the following equation:
2x + (-2) = 0
Simplifying this equation, we get:
2x - 2 = 0
From this, we can determine that x, which represents the oxidation state of oxygen, is equal to +2.
Now that we know the oxidation state of oxygen is -2, we can calculate the oxidation state of magnesium by using the overall charge of the compound, which is also 0.
The equation is:
(+2) + 2(-2) = 0
This simplifies to:
+2 - 4 = 0
Therefore, the oxidation state of elemental magnesium in this reaction is +2. So, the answer is +2.