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Example Questions
Example Question #2 : Titrations
Determine the volume in mL of solution it would take to neutralize of a with a solution during a titration.
Determine the moles of used:
At the equivalence point of the titration:
Convert the moles of to liters:
Convert the liters to milliliters:
Example Question #3 : Titrations
reacts with in aqueous solution according to the chemical equation provided. If it took of a solution to titrate of an solution, what was the concentration of original solution?
Using the concentration of as a conversion factor, we can convert the volume of to moles by dimensional analysis:
At the equivalence point of the titration:
Example Question #3 : Titrations
Household vinegar contains the organic compound acetic acid with chemical formula, . Acetic acid reacts with in aqueous solution according to the chemical equation provided. Determine the percentage (by volume) of vinegar in a sample that reacted with of during a titration to reach the equivalence. (Density of =)
At the equivalence point of the titration:
Convert the moles of to grams:
Using the density of given, convert the grams to mL:
Determine the percentage of by dividing the volume of by the total volume of vinegar:
Example Question #1 : Titrations
reacts with in aqueous solution according to the chemical equation provided. If it took of a solution to titrate of an solution, what was the concentration of original solution?
Using the concentration of as a conversion factor, we can convert the volume of to moles by dimensional analysis:
At the equivalence point of the titration:
Example Question #1 : Titrations
Household vinegar contains the organic compound acetic acid with chemical formula, . Acetic acid reacts with in aqueous solution according to the chemical equation provided. Determine the percentage (by volume) of acetic acid in a sample of vinegar that reacted with of during a titration to reach the equivalence. (Density of =)
Convert the liters of to moles:
At the equivalence point of the titration:
Convert the moles of to grams:
Using the density of given, convert the grams to mL:
Determine the percentage of by dividing the volume of by the total volume of vinegar:
Example Question #11 : Acid Base Reactions
Determine the pH of a solution that is .
Since is a strong acid, the concentration of is equal to the concentration of the acid itself.
Thus, .
Recall how to find the pH of a solution:
Plug in the given hydronium ion concentration to find the pH of the given solution.
Remember to maintain the correct number of significant figures.
Example Question #12 : Acid Base Reactions
Find the pH for a solution that is by mass. Assume a density of for the solution.
Start by assuming that there is liter of the solution. From this, we can use the given density to find the mass of the solution.
Next, find the mass of that is present in the solution.
Now, find the number of moles of that is present in the solution.
Since we initially assumed that we had liter of the solution, we now also know the concentration of in this solution.
Since is a strong acid, the concentration of hydronium ions in the solution will be the same as the concentration of .
Recall how to find the pH of a solution.
Example Question #13 : Acid Base Reactions
Find the pH of a solution that is by mass. Assume a density of for the solution.
Start by assuming that there is liter of the solution. From this, we can use the given density to find the mass of the solution.
Next, find the mass of that is present in the solution.
Now, find the number of moles of that is present in the solution.
Since we initially assumed that we had liter of the solution, we now also know the concentration of in this solution.
Since is a strong acid, the concentration of hydronium ions in the solution will be the same as the concentration of .
Recall how to find the pH of a solution.
Example Question #1 : P H
Which of the following techniques will decrease the pH of a solution?
Decreasing the concentration of protons
Increasing the amount of Hydroxide molecules
Adding more acid at the same Molarity of the solution
Increasing the concentration of protons
Increasing the amount of solvent
Increasing the concentration of protons
Increasing the concentration of protons of a solution will make the solution more acidic; therefore, it lowers the solution’s pH. Decreasing the concentration of protons will make the solution more basic, raising the pH. Adding more acid of the same molarity of the original solution will not increase the concentration of protons and will not increase acidity or lower the pH. Increasing the amount of hydroxide ions will make the solution more basic and raise the pH. Increasing the amount of solvent will lower the concentration, affecting molarity and not lowering the pH.
Example Question #14 : Acid Base Reactions
What is the of a solution that contains hydrofluoric acid and fluoride?
Note: for hydrofluoric acid.
In this question, we're given the concentrations of both a weak acid and its conjugate base in solution. We're also provided with the acid-dissociation constant for this acid, and we're asked to find the pH of the solution.
The easiest way to go about solving this problem is to first convert the acid-dissociation constant given into pKa. Then, we can use the Henderson-Hasselbalch equation to solve for the pH of this solution.
Now that we have the pKa, we can use it, along with the concentrations of the weak acid and its conjugate base, in order to solve for the pH of the solution.