Name_____________________________
Period ____Date____________
Activity: Strong vs. Weak Acids (Targets 11.3, 11.7, 11.8)
Instructions:
Go to the following simulation:
https://phet.colorado.edu/sims/html/acid-base-
solutions/latest/acid-base-solutions_en.html
Click on “My Solution”
Pre-lab:
1.) Write the dissociations for the follow acids:
HCl (strong): ____H+ Cl-___________________________________
HC2H3O2 (weak): ____C2H3O2- + H3O+________________________________
2.) What is the difference in how strong and weak acids dissociate in water?
The ions of strong acids and bases easily dissociate to completely dissolve in water, forming
m
er as
H hydrogen ions with a charge of plus one or OH - hydroxide ions with a charge of minus
co
one. Weak acids and bases only partially dissociate, leaving fewer ions in solution
eH w
o.
rs e
Part A: Strong Acid dissociations versus Weak Acid Dissociations
1. In the simulation, use the slider and set the initial concentration
Graph
ou urc
to 0.010 M and set the acid strength to “strong”.
2. Under Views, click molecules. How do the numbers of
o
molecules of the molecular acid compare to the number of
aC s
cations and anions?
vi y re
___There are more molecules of acid
________________________________________________
___________________________________________________
for
ed d
3. Under views, click Graph. Sketch the bar graph in the box Strong Acid
ar stu
provided. Ignore water.
4. Under view click back to “molecules”. Now change the acid strength to “weak”. How does the weak
is
acid bar graph differ from the strong acid? Why? Graph for Weak A
____Because it have a weak acid that do not dissociate in water also it
Th
has HA molecules
_______________________________________________
___________________________________________________
___________________________________________________
sh
___________________________________________________
5. Under views, click Graph. Sketch the bar graph to the right.
Ignore water.
6. Summary Questions: Which has more [H+] in solution – the cid
strong or weak acid? How do you know from looking at pH that
this solution has more [H+]? (Hint: Is the solution more acidic or
less acidic?)
This study source was downloaded by 100000807299931 from CourseHero.com on 12-07-2021 02:39:58 GMT -06:00
https://www.coursehero.com/file/120821769/Aciddocx/
___So all is in acid but if it is strong it is very acid and if so weak it is close to the base
part________________________________________________
___________________________________________________
___________________________________________________
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Part B: pH, [H+] for strong acids versus weak acids.
1. In the simulation, set initial concentration to 0.0010 M and set the strength to “strong”. Under views,
click “molecules”.
2. Move the pH probe into the beaker. Record the pH in the table below.
3. Change the strength to “weak”. Record the pH in the table below.
4. Repeat for the other concentrations listed in the table below.
Initial pH for Strong Acid pH for Weak Acid
Concentration
0.0010 M 2.05 4.52
0.010 M 2 4.5
0.10 M 1 4
m
1.0 M 0 3.5
er as
co
eH w
5. In general, what happens to pH as acid concentration increases?
o.
rs e
___Ph decreases___________________________________________________________________
ou urc
______________________________________________________________________
______________________________________________________________________
o
6. Compare the strong acid and the weak acid at the same concentration.
aC s
a. How do their pHs differ?
vi y re
_That the weak acid is more than that strong one this means that it is much closer to the base
_____________________________________________________________________
______________________________________________________________________
ed d
______________________________________________________________________
ar stu
b. Explain why the pH for a strong acid would be different from a weak acid. Relate how they
dissociate, their [H+] and their pHs.
is
____Ph is very low to the strong acid because it has mor H+ than the weak acid also the weak
acid does not dissociate in. water like the strong one
Th
__________________________________________________________________
______________________________________________________________________
______________________________________________________________________
sh
This study source was downloaded by 100000807299931 from CourseHero.com on 12-07-2021 02:39:58 GMT -06:00
https://www.coursehero.com/file/120821769/Aciddocx/
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