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
Otrada [13]
3 years ago
15

Your task is to create a buffered solution. You are provided with 0.10 M solutions of formic acid and sodium formate. Formic aci

d has a pKa of 3.75. 2. Create approximately 20 mL of buffer solution with a pH of 4.25.
Chemistry
1 answer:
Anton [14]3 years ago
4 0

Answer:

15.2mL of the 0.10M sodium formate solution and 4.8mL of the 0.10M formic acid solution.

Explanation:

To find the pH of a buffer based on the concentration of the acid and conjugate base we must use Henderson-Hasselbalch equation:

pH = pKa + log [A⁻] / [HA]

<em>Where [A⁻] could be taken as moles of the sodium formate and [HA] moles of the formic acid</em>

<em />

4.25 = 3.75 + log [A⁻] / [HA]

0.5 = log [A⁻] / [HA]

3.162 = [A⁻] / [HA] <em>(1)</em>

<em></em>

As both solutions are 0.10M and you want to create 20mL of the buffer, the moles are:

0.10M  * 20x10⁻³L =

2x10⁻³moles = [A⁻] + [HA] <em>(2)</em>

Replacing (2) in (1):

3.162 = 2x10⁻³moles - [HA] / [HA]

3.162 [HA] = 2x10⁻³moles - [HA]

4.162[HA] = 2x10⁻³moles

[HA] = 4.805x10⁻⁴ moles

[A⁻] = 2x10⁻³moles - 4.805x10⁻⁴ moles = 1.5195x10⁻³moles

That means, to create the buffer you must add:

[A⁻] = 1.5195x10⁻³moles * (1L / 0.10mol) = 0.0152L =

<h3>15.2mL of the 0.10M sodium formate solution</h3>

[HA] = 4.805x10⁻⁴ moles * (1L / 0.10mol) = 0.0048L =

<h3>4.8mL of the 0.10M formic acid solution</h3>
You might be interested in
How many moles are in 2.10 grams of KCr(SO4)2 • 12H2O
mart [117]

Answer:

42996.19989

Explanation:

Molar mass of KCr(SO4)2 12h2o is 20474.3809 g/mol x 2.1 = 42996.19989

8 0
3 years ago
When an object starts moving on its own,potential energy becomes kinetic energy.?
igomit [66]
Yes because an object has kinetic energy when its moving only, and has only potential energy when velocity is zero and there is height but for your statement to be true,the object has to have some height so there can be potential which can become kinetic energy 
7 0
3 years ago
A compound is a substance composed of two or more elements that are
Bad White [126]
Made of two or more diffrent elements cheamically bonded together.

Hope this helps
4 0
2 years ago
A mixture consists of sand and an aqueous salt
Alenkinab [10]

Answer is (4).<span>
<em>
</em>
</span>

<span><em>Explanation:</em>
</span><span>
<span>The given mixture contains an </span>insoluble solid<span> <span>and an </span></span>aqueous solution of salt.  <span>The insoluble solid is </span>sand. <span>

First </span><span>we have to separate </span>insoluble solid. <span>Sand can be separated by doing </span>filtration. When we filter the mixture sand can be seen as the residue on the filter paper. 

<span>After filtering the mixture, we should collect the </span>filtrate. <span>Filtrate is the </span>salt solution. <span>By doing </span>evaporation <span>we can get the </span>solid salt. <span>

First </span>and second choices are wrong <span>because </span>after evaporating water filtration cannot be done and salt and sand will be mixed together.<span>

Salt cannot be filtered out because the salt is soluble and it is <span>in aqueous medium. Hence, third choice is wrong</span></span></span>

7 0
3 years ago
Read 2 more answers
Which compounds are bases in aqueous solution according to brønsted–lowry theory?.
Fittoniya [83]

Ammonia compounds are bases in aqueous solution according to brønsted–lowry theory.

<h3>What are bases?</h3>

A base is a substance that can neutralize the acid by reacting with hydrogen ions.

Ammonia compounds are based on an aqueous solution according to brønsted–lowry theory because the water molecule donates a hydrogen ion to the ammonia, it is the Brønsted-Lowry acid, while the ammonia molecule which accepts the hydrogen ion is the Brønsted-Lowry base. Thus, ammonia acts as a base in both the Arrhenius sense and the Brønsted-Lowry sense.

Hence, ammonia compounds are based on an aqueous solution according to brønsted–lowry theory.

Learn more about the  bases here:

brainly.com/question/16387395

#SPJ1

3 0
2 years ago
Other questions:
  • If you have 220 liters O2 at STP how many moles of O2 do you have
    8·1 answer
  • How many grams of caf2 would be needed to produce 8.41×10-1 moles of f2?
    9·1 answer
  • How will the concentration of H+ and OH− ions change when a substance with a pH 11.4 is added to water?
    13·2 answers
  • Which element must be present in an organic compound?(1) hydrogen (3) carbon(2) oxygen (4) nitrogen
    10·2 answers
  • Which trait is inherited? (1 point)<br>physical fitness<br>scars <br>hair length<br>freckles​
    7·2 answers
  • Based on the number of valence electrons indicated by its location in the periodic table ,which elements behavior would you pred
    12·1 answer
  • Equal masses of carbon dioxide (CO2) and oxygen (O2) are mixed. What is the mole
    13·1 answer
  • What has the highest ionization energy Na, Mg, Al
    8·1 answer
  • Which of an Adams electrons are involved in chemical reactions
    11·1 answer
  • 1. When conducting this experiment, some procedures call for heating the substance several times and recording the mass after ea
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!