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
vagabundo [1.1K]
2 years ago
6

How many grams of NaF should be added to 500 mL of a 0.100 M solution of HF to make a buffer with a pH of 3.2

Chemistry
1 answer:
Korolek [52]2 years ago
4 0

Answer:

2.25g of NaF are needed to prepare the buffer of pH = 3.2

Explanation:

The mixture of a weak acid (HF) with its conjugate base (NaF), produce a buffer. To find the pH of a buffer we must use H-H equation:

pH = pKa + log [A-] / [HA]

<em>Where pH is the pH of the buffer that you want = 3.2, pKa is the pKa of HF = 3.17, and [] could be taken as the moles of A-, the conjugate base (NaF) and the weak acid, HA, (HF). </em>

The moles of HF are:

500mL = 0.500L * (0.100mol/L) = 0.0500 moles HF

Replacing:

3.2 = 3.17 + log [A-] / [0.0500moles]

0.03 = log [A-] / [0.0500moles]

1.017152 = [A-] / [0.0500moles]

[A-] = 0.0500mol * 1.017152

[A-] = 0.0536 moles NaF

The mass could be obtained using the molar mass of NaF (41.99g/mol):

0.0536 moles NaF * (41.99g/mol) =

<h3>2.25g of NaF are needed to prepare the buffer of pH = 3.2</h3>
You might be interested in
I just need 4-8! Plz hurry!!!!!!!!!!!
RSB [31]

Answer:

4: 90N

5: 7.77777m/s

6: 4

7: 12.5609756098

8: 187.5

Explanation:

8 0
3 years ago
Nitrogen fixing bacteria in soil turns nitrogen gas into
Alika [10]
<span>Nitrogen gas is converted to nitrate compounds by nitrogen-fixing bacteria in soil turns nitrogen gas into root nodules. Nitrogen is the most commonly limiting nutrient in plants. Legumes use nitrogen fixing bacteria, specifically symbiotic rhizobia bacteria, within their root nodules to counter the limitation.</span>
4 0
3 years ago
A compound's properties are different than the properties of the elements that make it up.
yan [13]
The answer is True because elements in a compound combine and become an entirely different substance with its own unique properties.
7 0
3 years ago
What is the mass of ethanol thats exacly fills a 200.0ml container
yaroslaw [1]

Answer:

158g

Explanation:

3 0
3 years ago
Because of friction?
Zanzabum

Answer:

what do you mean?

Explanation:

5 0
2 years ago
Read 2 more answers
Other questions:
  • The activity of a radioactive substance depends on ?​
    12·1 answer
  • Can someone help me please
    8·1 answer
  • What reaction is depicted by the given equation:<br> Au3+ + 3e− Au
    13·1 answer
  • Why is water considered "sticky"? What does that mean?
    5·2 answers
  • Describe one technology used to travel to space and one technology used to return from space
    7·1 answer
  • Thermal decomposition of 5.00 metric tons of limestone to lime and carbon dioxide requires 9.00 × 106 kJ of heat. Convert this e
    14·1 answer
  • All formulas of mole concept​
    8·1 answer
  • What is a chemical reaction that absorbs heat called?
    15·2 answers
  • I really need these solved, it’s asking for half equations!!
    14·1 answer
  • A bicycle is traveling at 14 miles per hour. How many feet will it cover in 55 seconds? Round your answer to the nearest tenth o
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!