Acids and Bases - AP Chemistry
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All acids have which phase label?
All acids have which phase label?
Acids are soluble in water substance, but remember, only water gets the liquid (l) phase label. Since acids are almost always dissolved in water, we use the (aq) subscript at the end of the chemical formula to indicate its phase.
Acids are soluble in water substance, but remember, only water gets the liquid (l) phase label. Since acids are almost always dissolved in water, we use the (aq) subscript at the end of the chemical formula to indicate its phase.
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What is the Bronsted-Lowry definition of acids?
What is the Bronsted-Lowry definition of acids?
According to the Bronsted-Lowry definition, acids are hydrogen donors.
According to the Bronsted-Lowry definition, acids are hydrogen donors.
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What is the definition of a Bronsted-Lowry base?
What is the definition of a Bronsted-Lowry base?
According to the Bronsted-Lowry definition, bases are hydrogen acceptors.
According to the Bronsted-Lowry definition, bases are hydrogen acceptors.
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According to the Arrhenius definition, acids __________.
According to the Arrhenius definition, acids __________.
According to the Arrhenius definition, acids increase the concentration of hydrogen ions in a solution.
According to the Arrhenius definition, acids increase the concentration of hydrogen ions in a solution.
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According to the Arrhenius definition __________.
According to the Arrhenius definition __________.
According to theArrhenius definition, bases increase the concentration of hydroxide ions in a solution.
According to theArrhenius definition, bases increase the concentration of hydroxide ions in a solution.
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According to the Lewis definition, acids are __________.
According to the Lewis definition, acids are __________.
According to the Lewis definition, acids are electron pair acceptors.
According to the Lewis definition, acids are electron pair acceptors.
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What is the Lewis definition of bases?
What is the Lewis definition of bases?
According to the Lewis definition, bases are electron pair donors.
According to the Lewis definition, bases are electron pair donors.
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What does amphoteric mean?
What does amphoteric mean?
An amphoteric substance is one that can act either as an acid or a base. Amino acids are good examples of amphoteric substances; they have a carboxylic acid group that can be acidic, and an amino group that can be basic.
An amphoteric substance is one that can act either as an acid or a base. Amino acids are good examples of amphoteric substances; they have a carboxylic acid group that can be acidic, and an amino group that can be basic.
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A buffer solution is a solution that __________.
A buffer solution is a solution that __________.
A buffer solution is used to keep the pH of the solution within a relatively narrow range. It must resist change in pH upon addition of acids or bases. A weak acid is used to lower the pH in response to addition of base or removal of acid, and its conjugate base is used to raise the pH in response to addition of acid or removal of base.
A buffer solution is used to keep the pH of the solution within a relatively narrow range. It must resist change in pH upon addition of acids or bases. A weak acid is used to lower the pH in response to addition of base or removal of acid, and its conjugate base is used to raise the pH in response to addition of acid or removal of base.
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There are __________ hydrogen ions in a solution with a pH of 3 than in a solution with a pH of 6.
There are __________ hydrogen ions in a solution with a pH of 3 than in a solution with a pH of 6.
Each whole number on the pH scale represents a factor of ten difference in concentration of hydrogen ions. We con verify this by finding the hydrogen ion concentrations for the two given pH values.
If we take the ratio of these values, we can see that there is a difference of 1000-times more protons in the solution with a pH of 3.
Each whole number on the pH scale represents a factor of ten difference in concentration of hydrogen ions. We con verify this by finding the hydrogen ion concentrations for the two given pH values.
If we take the ratio of these values, we can see that there is a difference of 1000-times more protons in the solution with a pH of 3.
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A sample of gastric juice has a pH of 2.5. What is the hydrogen ion concentration in this secretion?
A sample of gastric juice has a pH of 2.5. What is the hydrogen ion concentration in this secretion?
The concentration of hydrogen ions must lie somewhere between 
and 
; alternatively stated, it is between 
and 
. The pH of a solution with hydrogen ion concentration of 
will be 3, and the pH of a solution with hydrogen ion concentration 
will be 2; thus, our concentration must lie between these two values, since our pH is 2.5
To find the exact concentration, you must be familiar with the logarithmic scale. A difference of 0.5 is equivalent to a log of 3.
Our answer must therefore be 
, or 
.
We can calculate the pH in reverse to check our answer.
The concentration of hydrogen ions must lie somewhere between
To find the exact concentration, you must be familiar with the logarithmic scale. A difference of 0.5 is equivalent to a log of 3.
Our answer must therefore be
We can calculate the pH in reverse to check our answer.
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Sodium hydroxide is a strong base. What is the pH of a 0.02M sodium hydroxide solution?
Sodium hydroxide is a strong base. What is the pH of a 0.02M sodium hydroxide solution?
Since sodium hydroxide is a strong base, it will dissociate completely in water. This means that the concentration of the base will be equal to the concentration of hydroxide ions after the reaction runs to completion.
We can find the concentration of hydroxide ions via stoichiometry. One hydroxide ion is created from each molecule of sodium hydroxide that dissociates.
Since we have the concentration of hydroxide ions, we can solve for the pOH of the solution.
The question asks us to find the pH of the solution, so we will need to convert pOH to pH. To do so, we simply subtract the pOH from 14.
The pH of the solution is 12.3. Because sodium hydroxide is a strong base, it makes sense that the pH is above 7.
Since sodium hydroxide is a strong base, it will dissociate completely in water. This means that the concentration of the base will be equal to the concentration of hydroxide ions after the reaction runs to completion.
We can find the concentration of hydroxide ions via stoichiometry. One hydroxide ion is created from each molecule of sodium hydroxide that dissociates.
Since we have the concentration of hydroxide ions, we can solve for the pOH of the solution.
The question asks us to find the pH of the solution, so we will need to convert pOH to pH. To do so, we simply subtract the pOH from 14.
The pH of the solution is 12.3. Because sodium hydroxide is a strong base, it makes sense that the pH is above 7.
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Acids and bases can be described in three principal ways. The Arrhenius definition is the most restrictive. It limits acids and bases to species that donate protons and hydroxide ions in solution, respectively. Examples of such acids include HCl and HBr, while KOH and NaOH are examples of bases. When in aqueous solution, these acids proceed to an equilibrium state through a dissociation reaction.
All of the bases proceed in a similar fashion.
The Brønsted-Lowry definition of an acid is a more inclusive approach. All Arrhenius acids and bases are also Brønsted-Lowry acids and bases, but the converse is not true. Brønsted-Lowry acids still reach equilibrium through the same dissociation reaction as Arrhenius acids, but the acid character is defined by different parameters. The Brønsted-Lowry definition considers bases to be hydroxide donors, like the Arrhenius definition, but also includes conjugate bases such as the A- in the above reaction. In the reverse reaction, A- accepts the proton to regenerate HA. The Brønsted-Lowry definition thus defines bases as proton acceptors, and acids as proton donors.
The pH of a solution of 
is lowered from 4 to 3, and then from 3 to 2. Which of the following is the most accurate description of what happens during these transitions?
Acids and bases can be described in three principal ways. The Arrhenius definition is the most restrictive. It limits acids and bases to species that donate protons and hydroxide ions in solution, respectively. Examples of such acids include HCl and HBr, while KOH and NaOH are examples of bases. When in aqueous solution, these acids proceed to an equilibrium state through a dissociation reaction.
All of the bases proceed in a similar fashion.
The Brønsted-Lowry definition of an acid is a more inclusive approach. All Arrhenius acids and bases are also Brønsted-Lowry acids and bases, but the converse is not true. Brønsted-Lowry acids still reach equilibrium through the same dissociation reaction as Arrhenius acids, but the acid character is defined by different parameters. The Brønsted-Lowry definition considers bases to be hydroxide donors, like the Arrhenius definition, but also includes conjugate bases such as the A- in the above reaction. In the reverse reaction, A- accepts the proton to regenerate HA. The Brønsted-Lowry definition thus defines bases as proton acceptors, and acids as proton donors.
The pH of a solution of
The pH scale is logarithmic. Every pH unit drop corresponds to a tenfold increase in protons.
The pH scale is logarithmic. Every pH unit drop corresponds to a tenfold increase in protons.
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Acids and bases can be described in three principal ways. The Arrhenius definition is the most restrictive. It limits acids and bases to species that donate protons and hydroxide ions in solution, respectively. Examples of such acids include HCl and HBr, while KOH and NaOH are examples of bases. When in aqueous solution, these acids proceed to an equilibrium state through a dissociation reaction.
All of the bases proceed in a similar fashion.
The Brønsted-Lowry definition of an acid is a more inclusive approach. All Arrhenius acids and bases are also Brønsted-Lowry acids and bases, but the converse is not true. Brønsted-Lowry acids still reach equilibrium through the same dissociation reaction as Arrhenius acids, but the acid character is defined by different parameters. The Brønsted-Lowry definition considers bases to be hydroxide donors, like the Arrhenius definition, but also includes conjugate bases such as the A- in the above reaction. In the reverse reaction, A- accepts the proton to regenerate HA. The Brønsted-Lowry definition thus defines bases as proton acceptors, and acids as proton donors.
A scientist is studying an aqueous sample of 
, and finds that the hydroxide concentration is 
. Which of the following is true?
Acids and bases can be described in three principal ways. The Arrhenius definition is the most restrictive. It limits acids and bases to species that donate protons and hydroxide ions in solution, respectively. Examples of such acids include HCl and HBr, while KOH and NaOH are examples of bases. When in aqueous solution, these acids proceed to an equilibrium state through a dissociation reaction.
All of the bases proceed in a similar fashion.
The Brønsted-Lowry definition of an acid is a more inclusive approach. All Arrhenius acids and bases are also Brønsted-Lowry acids and bases, but the converse is not true. Brønsted-Lowry acids still reach equilibrium through the same dissociation reaction as Arrhenius acids, but the acid character is defined by different parameters. The Brønsted-Lowry definition considers bases to be hydroxide donors, like the Arrhenius definition, but also includes conjugate bases such as the A- in the above reaction. In the reverse reaction, A- accepts the proton to regenerate HA. The Brønsted-Lowry definition thus defines bases as proton acceptors, and acids as proton donors.
A scientist is studying an aqueous sample of
Given the hydroxide ion concentration, we will need to work using pOH to find the pH. We know that the sum of pH and pOH is equal to 14.
Use our value for the concentration to find the pOH.
Now that we have the pOH, we can use it to solve for the pH.
Given the hydroxide ion concentration, we will need to work using pOH to find the pH. We know that the sum of pH and pOH is equal to 14.
Use our value for the concentration to find the pOH.
Now that we have the pOH, we can use it to solve for the pH.
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Hydrochloric acid (HCl) is which of the following?
Hydrochloric acid (HCl) is which of the following?
Strong acids and bases dissociate completely into ions when placed in an aqueous solution. In contrast, weak acids and bases do not completely dissociate.
There are only six strong acids: perchloric acid (HClO4), hydroiodic acid (HI), hydrobromic acid (HBr), hydrochloric acid (HCl), nitric acid (HNO3), and sulfuric acid (H2SO4).
Strong acids and bases dissociate completely into ions when placed in an aqueous solution. In contrast, weak acids and bases do not completely dissociate.
There are only six strong acids: perchloric acid (HClO4), hydroiodic acid (HI), hydrobromic acid (HBr), hydrochloric acid (HCl), nitric acid (HNO3), and sulfuric acid (H2SO4).
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What is the pOH of a 
aqueous solution of 
?
What is the pOH of a
The first step for this problem is to find the pH. We can then derive the pOH from the pH value.
The pH is given by the equation 
. Since hydrochloric acid is monoprotic, the concentration of the solution is equal to the concentration of protons.
Using this value and the pH equation, we can calculate the pH.
Now we can find the pOH. The sum of the pH and the pOH is always 14.
The pOH of the solution is 7.8.
Alternatively, a shortcut can be used to estimate the pH. If 
is in the form 
, then pH is roughly 
.
For this question, this shortcut gets us a pH of 6.4, which produces a pOH of 7.6; very close to the real answer!
The first step for this problem is to find the pH. We can then derive the pOH from the pH value.
The pH is given by the equation
Using this value and the pH equation, we can calculate the pH.
Now we can find the pOH. The sum of the pH and the pOH is always 14.
The pOH of the solution is 7.8.
Alternatively, a shortcut can be used to estimate the pH. If
For this question, this shortcut gets us a pH of 6.4, which produces a pOH of 7.6; very close to the real answer!
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An arterial blood sample from a patient has a pH of 7.4. One day later, the same patient has an arterial blood pH of 7.15. How many times more acidic is the patient's blood on the second day?
An arterial blood sample from a patient has a pH of 7.4. One day later, the same patient has an arterial blood pH of 7.15. How many times more acidic is the patient's blood on the second day?
The equation to calculate pH is:
The normal pH of arterial blood is around 7.4. This reflects a concentration of hydrogen ions that can be found using the pH equation.
Using similar calculations for the second blood sample, we can find the hydrogen ion concentration again.
Now that we have both concentrations, can find the ratio of the acidity of the two samples.
You may know from biological sciences that this is approaching a lethal level of acidosis.
The equation to calculate pH is:
The normal pH of arterial blood is around 7.4. This reflects a concentration of hydrogen ions that can be found using the pH equation.
Using similar calculations for the second blood sample, we can find the hydrogen ion concentration again.
Now that we have both concentrations, can find the ratio of the acidity of the two samples.
You may know from biological sciences that this is approaching a lethal level of acidosis.
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You are presented with a solution that has a pOH of 2.13. What is the pH of this solution?
You are presented with a solution that has a pOH of 2.13. What is the pH of this solution?
pH and pOH are the log concentrations of protons and hydroxide ions, respectively.
The sum of pH and pOH is always 14. This is because the product of proton concentration and hydroxide concentration must always equal the equilibrium constant for the ionization of water, which is equal to 
.
In this question, we know that the pOH is equal to 2.13, allowing us to solve for the pH.
pH and pOH are the log concentrations of protons and hydroxide ions, respectively.
The sum of pH and pOH is always 14. This is because the product of proton concentration and hydroxide concentration must always equal the equilibrium constant for the ionization of water, which is equal to
In this question, we know that the pOH is equal to 2.13, allowing us to solve for the pH.
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What is the pH for a 0.05M solution of hydrochloric acid?
What is the pH for a 0.05M solution of hydrochloric acid?
Hydrochloric acid is a strong monoprotic acid, meaning that it will dissociate completely in solution and generate one proton from each acid molecule. This means that a 0.05M solution of hydrochloric acid will result in a 0.05M concentration of protons.
The equation for pH is as follows:
Hydrochloric acid is a strong monoprotic acid, meaning that it will dissociate completely in solution and generate one proton from each acid molecule. This means that a 0.05M solution of hydrochloric acid will result in a 0.05M concentration of protons.
The equation for pH is as follows:
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How does the Brønsted-Lowry theory of acids and bases describe acids?
How does the Brønsted-Lowry theory of acids and bases describe acids?
There are three primary classifications of acids and bases.
Arrhenius acids yield protons when dissolved in solution, while Arrhenius bases yield hydroxide ions.
Brønsted-Lowry acids are protone donors, while Brønsted-Lowry bases are proton acceptors.
Lewis acids are electron acceptors, while Lewis bases are electron donors.
An acid that dissociates completely in solution is considered a strong acid due to its high Ka value.
There are three primary classifications of acids and bases.
Arrhenius acids yield protons when dissolved in solution, while Arrhenius bases yield hydroxide ions.
Brønsted-Lowry acids are protone donors, while Brønsted-Lowry bases are proton acceptors.
Lewis acids are electron acceptors, while Lewis bases are electron donors.
An acid that dissociates completely in solution is considered a strong acid due to its high Ka value.
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