1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
natita [175]
3 years ago
6

Remember from the buffering capacity note, tell me which of the following acids(and their salts) can make the best buffered solu

tion to maintain the pH as close to 4.30 as possible.
a. Chloroacetic acid (Ka = 1.35 x 10^-3)
b. Propanoic acid (Ka = 1.30 x 10^-5)
c. Benzoic acid (Ka = 6.40 x 10^-5)
d. Hypochlorous acid (Ka = 3.50 x 10^-8)

Hint:
Calculate the required concentration of hyrogen ions from pH 4.30 (use antilog function of your calculator)
You, now, know [H+] and Ka values of each acid. Plug in the formula
Ka = [H+] [A-] / [HA] , and solve for the ratio [HA] / [A-]. The acid with the
ratio [HA] / [A-] closest to 1 is the best (why?)
Advanced Placement (AP)
1 answer:
lakkis [162]3 years ago
6 0

Answer:

The answer is Benzoic acid. Hence, (C) is the correct answer. The acid with the  ratio [HA] / [A-] closest to 1 is the best because a buffer is most effective when the amounts of acid and conjugate base are approximately equal and hence their ratio should be close to 1.

Explanation:

pH = - log₁₀[H⁺]

[H⁺] = 10∧-pH

Given,

pH = 4.30

Chloroacetic acid (Ka = 1.35 x 10^-3)

Propanoic acid (Ka = 1.30 x 10^-5)

Benzoic acid (Ka = 6.40 x 10^-5)

Hypochlorous acid (Ka = 3.50 x 10^-8)  

Using the Hints,

The required [H+] = 10⁻⁴°³  => 5.011 x 10⁻⁵

Using the formula,

Ka = [H+] [A-] / [HA] and finding [HA] / [A-] values for each of the given acids.

[HA] / [A-] = [H+] /Ka

Substituting the values,

For Chloroacetic acid, [HA] / [A-] = 5.011 x 10⁻⁵ / 1.35 x 10⁻³ => 0.037

For Propanoic acid,  [HA] / [A-] = 5.011 x 10⁻⁵ / 1.30 x 10⁻⁵ =>  3.85

For Benzoic acid,  [HA] / [A-] = 5.011 x 10⁻⁵ / 6.40 x 10⁻⁵ => 0.782

For Hypochlorous acid,  [HA] / [A-] = 5.011 x 10⁻⁵ / 3.50 x 10⁻⁸ => 1431.714

As Benzoic acid has  [HA] / [A-] value closest to 1, it can make the best buffered solution.

The acid with the

ratio [HA] / [A-] closest to 1 is the best because,

A buffer is most effective when the amounts of acid and conjugate base are approximately equal and hence their ratio should be close to 1.

You might be interested in
STATISTICS HELP PLEASE #4
lbvjy [14]

Answer:

1 only

Explanation:

3 0
3 years ago
Read 2 more answers
What information is not included in a credit report?
jek_recluse [69]

I would believe that the credit report doesn't include race or ethnicity

4 0
2 years ago
1. The government of Brazil moved its capital city in 1960. Explain the reasons for this decision, and describe its effects on i
Alona [7]

Answer and Explanation:

1. The capital of Brazil was changed on April 21, 1960 by the president Jucelino Kubitschek, who built a city, called Brazilia, to become the country's federal capital instead of Rio de Janeiro, which was the old capital. He did this because Rio de Janeiro is very close to the ocean and he believed that it left the capital vulnerable to marine attacks, for this reason, he decided to move the capital to a more central region of the country, where it would be more protected.

2. Internal migration in Brazil occurs mainly due to economic factors, where citizens from the poorest states and with the worst living conditions (northeastern states) migrate to the producing centers of the country, which are the southeastern states, mainly São Paulo. Internal migration in China also has the economic condition as its main reason, however the Chinese are constantly migrating to the country's capital and need to submit to a series of laws and guidelines, while in Brazil, this process is done without any type of legislation or restriction.

8 0
3 years ago
Read 2 more answers
Technology is not available to everyone, particularly in developing countries. This lack of equitable technology distribution ac
Romashka-Z-Leto [24]

Answer:

Digital Divide

Explanation:

Technology is not available to everyone, particularly in developing countries. This lack of equitable technology distribution across age, race, education level, and Internet connection speed is called the Digital Divide. The major cause of the digital divide are as follows:

1. access

2. cost of technology

3. access for the disabled

4. lack of skills, lack of education

5 0
3 years ago
If the ratio of students with green shirts to total students in a class is 3 to 8, and are 12 students wearing green shirts, how
jekas [21]

Answer:

20

Explanation:

You would set up a proportion in order to solve this

3 green           12 green

------------     =   ------------

8 total                x total

Then you would cross mulitply for x and get 32. Since that is the total number, you would have to subract the 12 from 32 to get 20.

5 0
3 years ago
Read 2 more answers
Other questions:
  • If a robot were to do all that a human can do: What are the main things that the robot brain would need to do? Choose two functi
    9·1 answer
  • Question 9 "studies indicate that attaining a higher education degree improves job prospects
    15·1 answer
  • Read this excerpt from The Riddle of the Rosetta Stone by James Cross Giblin.
    14·2 answers
  • Find all the intervals on which the graph of the function is concave upward: f(x) = x^2 + 1/ x^2
    5·1 answer
  • What is meant by biodiversity? write with examples.<br>​
    9·2 answers
  • Describe a common characteristic shared by the coffee producing countries shown on the map.
    13·1 answer
  • Which of the following conclusions can be drawn from the data?
    7·1 answer
  • How do religious and ethnic groups both reflect and influence the geography of places at different
    14·1 answer
  • A school of fish would be an example of<br> what type of population distribution?
    8·1 answer
  • How much more did Isabel earn than Sarah
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!