Give the oxidation state for the metal ion in each of the following compounds, respectively:
K2O,CaO,TiO2,V2O5
The oxidation state of the metal ion in each of the compounds is as follows:
1. K2O: The oxidation state of oxygen (O) in compounds is typically -2. Since it's a compound with no other elements, the oxidation state of potassium (K) would be +1 for each potassium ion. Therefore, the oxidation state of the metal ion (potassium) is +1.
2. CaO: Similar to the previous compound, oxygen has an oxidation state of -2. Calcium (Ca) is an alkaline earth metal and typically has an oxidation state of +2 in compounds. Therefore, the oxidation state of the metal ion (calcium) is +2.
3. TiO2: Again, oxygen has an oxidation state of -2. Titanium (Ti) is a transition metal and can have various oxidation states. In TiO2, each oxygen atom contributes -4 towards the compound's charge. Since the compound is neutral, the titanium ion must have a total oxidation state of +4 to balance the charge. Therefore, the oxidation state of the metal ion (titanium) is +4.
4. V2O5: Oxygen has an oxidation state of -2. Vanadium (V) is another transition metal and can have various oxidation states. In V2O5, each oxygen atom contributes -10 towards the compound's charge. Since the compound is neutral, the vanadium ions must have a total oxidation state of +10 to balance the charge. Each vanadium ion would have an oxidation state of +5. Therefore, the oxidation state of the metal ion (vanadium) is +5.
To determine the oxidation state of a metal ion in a compound, you need to consider the overall charge of the compound and the known oxidation states of the other atoms.
Let's go through each compound:
1. K2O:
The overall charge of potassium oxide (K2O) is zero, since oxygen has an oxidation state of -2. The oxidation state of oxygen is usually -2 in most compounds, except when it is in a peroxide (O2^2-), superoxide (O2^-), or when oxygen bonds with fluorine (OF2). So, since there are two potassium ions (K^+) in the compound, each potassium ion must have a +1 oxidation state to balance out the -2 oxidation state of the oxygen ion. Therefore, the oxidation state of the metal ion (potassium) in K2O is +1.
2. CaO:
Similar to the previous compound, the overall charge of calcium oxide (CaO) is zero. Oxygen still has a -2 oxidation state, and calcium must have a +2 oxidation state to balance the charge. Therefore, the oxidation state of the metal ion (calcium) in CaO is +2.
3. TiO2:
In titanium dioxide (TiO2), the overall charge is also zero. Since each oxygen has a -2 oxidation state, the total oxidation state of the two oxygen atoms is -4. To balance this charge, the titanium (Ti) atom must have a +4 oxidation state. Therefore, the oxidation state of the metal ion (titanium) in TiO2 is +4.
4. V2O5:
The compound vanadium pentoxide (V2O5) has an overall charge of zero. Each oxygen atom has a -2 oxidation state, so the total oxidation state of the five oxygen atoms is -10. To balance this charge, each vanadium atom (V) must have a +5 oxidation state. Therefore, the oxidation state of the metal ion (vanadium) in V2O5 is +5.
Remember that the oxidation states of elements can vary in different compounds, so it's important to consider the specific compound and its overall charge when determining the oxidation state of a metal ion.
This set of rules will get the right answer for you.
http://www.chemteam.info/Redox/Redox-Rules.html