ACID-BASE EQUILIBRIA Flashcards
This is extremely important in stabilizing chemical reactions both in the laboratory and in homeostasis
Acid-base equilibria in aqueous solutions
The maintenance of the acid and base concentrations in the body within the narrow range that is required for the proper functioning of metabolic processes
homeostasis
The measurement of the hydrogen ion concentration, [H+] in aqueous solutions
acidity
It is neutral. It contains equal quantities of hydronium ions, HзO*, and hydroxide ions, OH.
Pure water
In acidic solutions the [H] ___ (less than, greater than, or equal?) [OH-]. The pH of acidic solutions is ________ and the POH _______.
- >
- less than 7
- greater than 7
Conversely in basic solutions the [OH-] ___ (less than, greater than, or equal?) [H’] and the pH is _____ and the pOH is _____.
- >
- greater than 7
- less than 7
The pH of a solution is measured by using a _____ which response electrically to the concentration of H+ ions.
pH meter
_________ are defined as those which completely dissociate in an aqueous solution. Therefore, the concentration of H or OH produced in the solution corresponds directly to the moles of H* or OH contained in the compound.
Strong acids and bases
When a _____ acid is dissolved in water, it does not dissociate completely but tends to hold onto some of the acidic protons.
weak
The _____ is directly related to the stability of the corresponding (conjugate) base; the more unstable the base, the fewer protons are released from the acid (the “weaker” it is).
strength of the acid
9 Materials used in exp 4?
- pH meters,
- HCI solution,
- NaOH,
- CH3COOH,
- beakers,
- graduated cylinders,
- sodium acetate,
- analytical balance,
- distilled water
In exp 4, what is the name of Test A?
The pH of Hydrochloric Acid Solutions
In exp 4, what is the name of Test B?
Determining the Ka of Acetic Acid
In exp 4, what is the name of Test C?
The effect of strong acid and base on the pH of Buffer Solutions
EXP 4-A:
* Obtain a ___ mL of a ___ M hydrochloric acid solution from the reagent shelf
- 60 mL
- 0.1 M
EXP 4-A:
* Use a _____ to transfer __ mL of this solution into a clean __ mL beaker. Label the beaker with the concentration of the acid
- graduated cylinder
- 50 mL
- 100 mL
EXP 4-A:
* Pipette __ mL of the remaining acid solution into a clean graduated cylinder. The graduated cylinder only needs to be rinsed with distilled water
5 mL
EXP 4-A:
* Dilute the __ mL to __ mL with distilled water. This solution is then transferred to a second ___ mL beaker and mixed thoroughly
- 5 mL
- 50 mL
- 100 mL
EXP 4-A:
* label the beaker with the ____ of this acid solution
concentration
EXP 4-A:
* Measure the ___ of each of the two solutions with a pH meter and record each ___
pH
EXP 4-B:
* Obtain ___ mL of a _____ M ____ solution from the reagent shelf
- 60
- 0.1
- acetic acid
EXP 4-B:
* Transfer __ mL of this solution to a clean ___ mL beaker by using a ___. Label the beaker with the acid concentration
- 50 mL
- 100 mL
- graduated cylinder
EXP 4-B:
* Pipette __ mL of the remaining Acid solution into a graduated cylinder and dilute to __ mL with distilled water in the graduated cylinder
- 5 mL
- 50 mL
EXP 4-B:
* Transfer this solution to a ___mL beaker and mix thoroughly. Label the beaker with the new _____ of the acid solution
- 100 mL
- concentration
EXP 4-B:
* Measure the ___ of each of the two solutions with a pH meter and record each pH
pH
EXP 4-C:
* Weigh a clean ___ mL beaker to the nearest ___ g
- 250 mL
- 0.1 g
EXP 4-C:
* Add __ g of _____ to the beaker
- 4.1 g
- solid sodium acetate
EXP 4-C:
* remove the beaker from the balance and using a graduated cylinder and add __ mL of __M acetic acid to it
- 8.5 mL
- 6M
EXP 4-C:
* Use a graduated cylinder to add __ mL of distilled water to the solution prepared in step 3. Stir the mixture until all the sodium acetate has dissolved
91.5 mL
EXP 4-C:
* Label ___ (quantity) clean 100 and/or 150 mL beakers, and label them ______
- four
- 1, 2, 3, 4
EXP 4-C:
* use a graduated cylinder to add __ mL of buffer solution to beakers ____ and __
- 40 mL
- Beakers 2 and 4
EXP 4-C:
* Add ___ mL of distilled water to beakers _ and ___. Be sure the graduated cylinder is well rinsed before using it
- 40 mL
- 1 and 3
EXP 4-C:
* record the ___ of each solution. Rinse the pH electrode with distilled water between readings
pH
EXP 4-C:
* Remove the ___, rinse it with distilled water and place it in a beaker containing distilled water. The __ should always be stored in distilled water
electrode
EXP 4-C:
* Pipette __ mL of __ hydrochloric acid solutions into beakers ___ and ___. Measure and record the pH for each solution after mixing well
- 1.0 mL
- 6M
- beakers 1 and 2
EXP 4-C:
* Pipette __ mL of __M sodium hydroxide into beakers __ and ___. Measure the pH for each solution after mixing well
- 1.0 mL
- 6M
- beakers 3 and 4
