All High School Chemistry Resources
Example Questions
Example Question #1 : Identifying Unknown Volume
What volume of 0.5M sulfuric acid is needed to neutralize 50mL of 0.5M potassium hydroxide?
Sulfuic acid is a diprotic acid and will give two hydrogen ions for each molecule of sulfuric acid that is completely dissociated. Potassium hydroxide has only one hyroxide ion per molecule.
Both of these compounds are strong, meaning they will dissociate completely in solution (potassium hydroxide is a strong base and sulfuric acid is a strong acid).
First, we need to find the moles of potassium hydroxide from the given volume and molarity.
Use stoichiometry to find the volume of sulfuric acid needed to react 0.1mol of potassium hydroxide.
Our final volume of sulfuric acid is 0.025L, or 25mL.
Example Question #81 : Acid Base Chemistry
A chemist has a bottle containing a 2M aqueous solution of hydrochloric acid. He needs to create a 50mL solution of hydrochloric acid that has a concentration of 0.5M. What is the volume of 2M hydrochloric acid that he should dilute in order to achieve the desired concentration?
In order to dilute the concentrated acid, we need to find the amount of concentrated acid that will be diluted to 50mL of total solution. We can find the volume of concentrated acid necessary by setting the final volume and concentration equal to the initial concentration and unknown volume.
The initial concentration is 2M, the final concentration is 0.5M, and the final volume is 50mL
This means that 12.5mL of concentrated acid needs to be diluted to 50mL of solution. This will result in a solution with a concentration of 0.5M.
Example Question #3 : Identifying Unknown Volume
Starting with 30mL of a .005M
solution, how many milliliters of .010M solution are needed to titrate it?
None of these
For this question use the following formula:
is the number of acidic hydrogens on the acid, is the molarity of the acid, is the volume of the acid, is the number of basic hydroxides on the base, is the molarity of the base, is the volume of the base
Rearrange the equation for the volume of the base:
Plug in known values and solve.
Example Question #3 : Identifying Unknown Volume
Starting with 50mL of a .015M
solution, how many milliliters of .010M solution are needed to titrate it?
None of these
For this question use the following formula:
is the number of acidic hydrogens on the acid, is the molarity of the acid, is the volume of the acid, is the number of basic hydroxides on the base, is the molarity of the base, is the volume of the base
Rearrange the equation for the volume of the base:
Plug in known values and solve.
Example Question #14 : Titrations
Starting with 25mL of a .001M
solution, how many milliliters of .010M solution are needed to titrate it?
None of these
For this question use the following formula:
is the number of acidic hydrogens on the acid, is the molarity of the acid, is the volume of the acid, is the number of basic hydroxides on the base, is the molarity of the base, is the volume of the base
Rearrange the equation for the volume of the base:
Plug in known values and solve.
Example Question #1 : Identifying Unknown Volume
Starting with 75mL of a .030M
solution, how many milliliters of .022M solution are needed to titrate it?
None of these
For this question use the following formula:
is the number of acidic hydrogens on the acid, is the molarity of the acid, is the volume of the acid, is the number of basic hydroxides on the base, is the molarity of the base, is the volume of the base
Rearrange the equation for the volume of the base:
Plug in known values and solve.
Example Question #2 : Identifying Unknown Volume
Starting with 12mL of a .015M
solution, how many milliliters of .000M solution are needed to titrate it?
None of these
For this question use the following formula:
is the number of acidic hydrogens on the acid, is the molarity of the acid, is the volume of the acid, is the number of basic hydroxides on the base, is the molarity of the base, is the volume of the base
Rearrange the equation for the volume of the base:
Plug in known values and solve.
Example Question #3 : Identifying Unknown Volume
Starting with 50mL of a .015M
solution, how many milliliters of .010M solution are needed to titrate it?
None of these
For this question use the following formula:
is the number of acidic hydrogens on the acid, is the molarity of the acid, is the volume of the acid, is the number of basic hydroxides on the base, is the molarity of the base, is the volume of the base
Rearrange the equation for the volume of the base:
Plug in known values and solve.