Oxidation State - AP Chemistry
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What is the oxidation number of chlorine in perchlorate?
What is the oxidation number of chlorine in perchlorate?
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Perchlorate is a complex ion with the formula 
.
The most important rule for oxidation number is that the sum of the oxidation states of the atoms must equal the overall molecular charge.
This compound has four oxygens, which always have a 
oxidation state.
Chlorine usually has an oxidation state of 
, but in this case it must balance out the oxygens.
Chlorine must be 
.
Perchlorate is a complex ion with the formula
The most important rule for oxidation number is that the sum of the oxidation states of the atoms must equal the overall molecular charge.
This compound has four oxygens, which always have a
Chlorine usually has an oxidation state of
Chlorine must be
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When is the oxidation number of H (-1)?
When is the oxidation number of H (-1)?
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We typically think of Hydrogen as having an oxidation number of +1. However when it is bonded to a less electronegative element such as Na it is actually assigned an oxidation number of -1.
We typically think of Hydrogen as having an oxidation number of +1. However when it is bonded to a less electronegative element such as Na it is actually assigned an oxidation number of -1.
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What is the oxidation number of Cr, S, and Fe in the following substances: (a) K2Cr2O7 (b) H2SO4 (c) Fe2O3.
What is the oxidation number of Cr, S, and Fe in the following substances: (a) K2Cr2O7 (b) H2SO4 (c) Fe2O3.
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(a) Since O has a –2 oxidation number and K has a +1 oxidation number (1 valence
electron it gives up), that means that Cr must have an oxidation number of +6. (b) Since H
has a +1 oxidation number and O has a –2 oxidation number, S has a +6 oxidation number.
(c) Fe has an oxidation number of +3 in order for it to have a net 0 oxidation state.
(a) Since O has a –2 oxidation number and K has a +1 oxidation number (1 valence
electron it gives up), that means that Cr must have an oxidation number of +6. (b) Since H
has a +1 oxidation number and O has a –2 oxidation number, S has a +6 oxidation number.
(c) Fe has an oxidation number of +3 in order for it to have a net 0 oxidation state.
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Consider the following balanced equation:
What is the difference between the oxidation state of aluminum on the right side of the equation versus the left?
Consider the following balanced equation:
What is the difference between the oxidation state of aluminum on the right side of the equation versus the left?
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On the left side of the equation, 
is a solid, so its oxidation state is zero, but on the right side it is in a salt, so it is not in its zero state.
Sulfate, 
, is an anionic salt, and there are three sulfate ions in each complex, yielding a net charge of -6. The two aluminum ions must have a net charge of +6, which, divided over two aluminum ions, yields an oxidation state of +3 for each aluminum ion.
The difference comes from simple subtraction: 
.
On the left side of the equation,
Sulfate,
The difference comes from simple subtraction:
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What is the oxidation number of manganese in 
?
What is the oxidation number of manganese in
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Potassium always has an oxidation state of 
, while oxygen always has an oxidation state of 
. Since we have four oxygens, there is a total charge of 
from them.
The most important rule of oxidation numbers is that their sum must equal the charge on the molecule. In this compound, we have 
.
Manganese needs to cancel out the charge from potassium and oxygen in order to give us a neutral compound.
Potassium always has an oxidation state of
The most important rule of oxidation numbers is that their sum must equal the charge on the molecule. In this compound, we have
Manganese needs to cancel out the charge from potassium and oxygen in order to give us a neutral compound.
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In the above reaction, what are the initial and final oxidation states of 
?
In the above reaction, what are the initial and final oxidation states of
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To determine the initial oxidation state of 
, we first must realize that 
has 3 oxygen atoms, each with a charge of 
, for a total charge contribution of 
. Furthermore, since 
has no net charge, the 
atoms must contribute a total charge of 
to balance out the 
charge coming from the oxygens. And since there are two 
atoms, then each must have a charge of 
.
On the product side of the reaction, notice that 
is all by itself without any charge. The oxidation state of any individual atom is 
.
To determine the initial oxidation state of
On the product side of the reaction, notice that
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The Claus process is used in the petroleum industry to convert sulfur containing gases into solid (rhombic) sulfur. One of the reactions that takes place in this process is:
Which of the following statements is correct:
The Claus process is used in the petroleum industry to convert sulfur containing gases into solid (rhombic) sulfur. One of the reactions that takes place in this process is:
Which of the following statements is correct:
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We have an oxidizing 
and a reducing 
agent, then is a red-ox reaction and the two semi reactions are:
(oxidation, 
losses electrons)
(reduction, 
gains electrons)
In total 32 electrons are transferred from the 
to 
.
We have an oxidizing
In total 32 electrons are transferred from the
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What is the oxidation number of nitrogen in 
?
What is the oxidation number of nitrogen in
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First, note that the molecule does not have a charge, meaning that the oxidation numbers of each atom must add up to zero. Hydrogen has an oxidation number of 
and oxygen has an oxidation number of 
. Thus, if we call the oxidation number of nitrogen 
, we can get the equation 
. Solving this gives 
, so the oxidation number of nitrogen is 
in this molecule.
First, note that the molecule does not have a charge, meaning that the oxidation numbers of each atom must add up to zero. Hydrogen has an oxidation number of 
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The following is a modified true/false question. In it, you must decide if each individual statement is true (T) or false (F). If both are true, then you must also decide if the second statement is a correct explanation (CE) of the first statement.
I: An 
ion would undergo reduction to form 
metal
BECAUSE
II: reduction is a loss of electrons
The following is a modified true/false question. In it, you must decide if each individual statement is true (T) or false (F). If both are true, then you must also decide if the second statement is a correct explanation (CE) of the first statement.
I: An 
BECAUSE
II: reduction is a loss of electrons
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Statement II is false: reduction is a gain of electrons. Looking at statement I, the ion's charge would decrease by 3 in becoming a metal, which suggests that the ion gains 3 electrons. Thus, it is undergoing reduction.
Statement II is false: reduction is a gain of electrons. Looking at statement I, the ion's charge would decrease by 3 in becoming a metal, which suggests that the ion gains 3 electrons. Thus, it is undergoing reduction.
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When is the oxidation number of H (-1)?
When is the oxidation number of H (-1)?
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We typically think of Hydrogen as having an oxidation number of +1. However when it is bonded to a less electronegative element such as Na it is actually assigned an oxidation number of -1.
We typically think of Hydrogen as having an oxidation number of +1. However when it is bonded to a less electronegative element such as Na it is actually assigned an oxidation number of -1.
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What is the oxidation number of Cr, S, and Fe in the following substances: (a) K2Cr2O7 (b) H2SO4 (c) Fe2O3.
What is the oxidation number of Cr, S, and Fe in the following substances: (a) K2Cr2O7 (b) H2SO4 (c) Fe2O3.
Tap to reveal answer
(a) Since O has a –2 oxidation number and K has a +1 oxidation number (1 valence
electron it gives up), that means that Cr must have an oxidation number of +6. (b) Since H
has a +1 oxidation number and O has a –2 oxidation number, S has a +6 oxidation number.
(c) Fe has an oxidation number of +3 in order for it to have a net 0 oxidation state.
(a) Since O has a –2 oxidation number and K has a +1 oxidation number (1 valence
electron it gives up), that means that Cr must have an oxidation number of +6. (b) Since H
has a +1 oxidation number and O has a –2 oxidation number, S has a +6 oxidation number.
(c) Fe has an oxidation number of +3 in order for it to have a net 0 oxidation state.
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Consider the following balanced equation:
What is the difference between the oxidation state of aluminum on the right side of the equation versus the left?
Consider the following balanced equation:
What is the difference between the oxidation state of aluminum on the right side of the equation versus the left?
Tap to reveal answer
On the left side of the equation, is a solid, so its oxidation state is zero, but on the right side it is in a salt, so it is not in its zero state.
Sulfate, , is an anionic salt, and there are three sulfate ions in each complex, yielding a net charge of -6. The two aluminum ions must have a net charge of +6, which, divided over two aluminum ions, yields an oxidation state of +3 for each aluminum ion.
The difference comes from simple subtraction: .
On the left side of the equation,
Sulfate,
The difference comes from simple subtraction:
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What is the oxidation number of manganese in ?
What is the oxidation number of manganese in
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Potassium always has an oxidation state of , while oxygen always has an oxidation state of . Since we have four oxygens, there is a total charge of from them.
The most important rule of oxidation numbers is that their sum must equal the charge on the molecule. In this compound, we have .
Manganese needs to cancel out the charge from potassium and oxygen in order to give us a neutral compound.
Potassium always has an oxidation state of
The most important rule of oxidation numbers is that their sum must equal the charge on the molecule. In this compound, we have
Manganese needs to cancel out the charge from potassium and oxygen in order to give us a neutral compound.
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What is the oxidation number of chlorine in perchlorate?
What is the oxidation number of chlorine in perchlorate?
Tap to reveal answer
Perchlorate is a complex ion with the formula .
The most important rule for oxidation number is that the sum of the oxidation states of the atoms must equal the overall molecular charge.
This compound has four oxygens, which always have a oxidation state.
Chlorine usually has an oxidation state of , but in this case it must balance out the oxygens.
Chlorine must be .
Perchlorate is a complex ion with the formula
The most important rule for oxidation number is that the sum of the oxidation states of the atoms must equal the overall molecular charge.
This compound has four oxygens, which always have a
Chlorine usually has an oxidation state of
Chlorine must be
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In the above reaction, what are the initial and final oxidation states of ?
In the above reaction, what are the initial and final oxidation states of
Tap to reveal answer
To determine the initial oxidation state of , we first must realize that has 3 oxygen atoms, each with a charge of , for a total charge contribution of . Furthermore, since has no net charge, the atoms must contribute a total charge of to balance out the charge coming from the oxygens. And since there are two atoms, then each must have a charge of .
On the product side of the reaction, notice that is all by itself without any charge. The oxidation state of any individual atom is .
To determine the initial oxidation state of
On the product side of the reaction, notice that
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The Claus process is used in the petroleum industry to convert sulfur containing gases into solid (rhombic) sulfur. One of the reactions that takes place in this process is:
Which of the following statements is correct:
The Claus process is used in the petroleum industry to convert sulfur containing gases into solid (rhombic) sulfur. One of the reactions that takes place in this process is:
Which of the following statements is correct:
Tap to reveal answer
We have an oxidizing and a reducing agent, then is a red-ox reaction and the two semi reactions are:
(oxidation, losses electrons)
(reduction, gains electrons)
In total 32 electrons are transferred from the to .
We have an oxidizing
In total 32 electrons are transferred from the
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When is the oxidation number of H (-1)?
When is the oxidation number of H (-1)?
Tap to reveal answer
We typically think of Hydrogen as having an oxidation number of +1. However when it is bonded to a less electronegative element such as Na it is actually assigned an oxidation number of -1.
We typically think of Hydrogen as having an oxidation number of +1. However when it is bonded to a less electronegative element such as Na it is actually assigned an oxidation number of -1.
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What is the oxidation number of Cr, S, and Fe in the following substances: (a) K2Cr2O7 (b) H2SO4 (c) Fe2O3.
What is the oxidation number of Cr, S, and Fe in the following substances: (a) K2Cr2O7 (b) H2SO4 (c) Fe2O3.
Tap to reveal answer
(a) Since O has a –2 oxidation number and K has a +1 oxidation number (1 valence
electron it gives up), that means that Cr must have an oxidation number of +6. (b) Since H
has a +1 oxidation number and O has a –2 oxidation number, S has a +6 oxidation number.
(c) Fe has an oxidation number of +3 in order for it to have a net 0 oxidation state.
(a) Since O has a –2 oxidation number and K has a +1 oxidation number (1 valence
electron it gives up), that means that Cr must have an oxidation number of +6. (b) Since H
has a +1 oxidation number and O has a –2 oxidation number, S has a +6 oxidation number.
(c) Fe has an oxidation number of +3 in order for it to have a net 0 oxidation state.
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Consider the following balanced equation:
What is the difference between the oxidation state of aluminum on the right side of the equation versus the left?
Consider the following balanced equation:
What is the difference between the oxidation state of aluminum on the right side of the equation versus the left?
Tap to reveal answer
On the left side of the equation, is a solid, so its oxidation state is zero, but on the right side it is in a salt, so it is not in its zero state.
Sulfate, , is an anionic salt, and there are three sulfate ions in each complex, yielding a net charge of -6. The two aluminum ions must have a net charge of +6, which, divided over two aluminum ions, yields an oxidation state of +3 for each aluminum ion.
The difference comes from simple subtraction: .
On the left side of the equation,
Sulfate,
The difference comes from simple subtraction:
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What is the oxidation number of manganese in ?
What is the oxidation number of manganese in
Tap to reveal answer
Potassium always has an oxidation state of , while oxygen always has an oxidation state of . Since we have four oxygens, there is a total charge of from them.
The most important rule of oxidation numbers is that their sum must equal the charge on the molecule. In this compound, we have .
Manganese needs to cancel out the charge from potassium and oxygen in order to give us a neutral compound.
Potassium always has an oxidation state of
The most important rule of oxidation numbers is that their sum must equal the charge on the molecule. In this compound, we have
Manganese needs to cancel out the charge from potassium and oxygen in order to give us a neutral compound.
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