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
almond37 [142]
3 years ago
7

"How much NH4Cl, when present in 2.00 liters of 0.200 M ammonia, will give a solution with pH = 8.20? For NH3, Kb = 1.8 x 10-5"

Chemistry
1 answer:
Andru [333]3 years ago
3 0

Answer:

245.66g of NH₄Cl is the mass we need to add to obtain the desire pH

Explanation:

The mixture of NH3/NH4Cl produce a buffer. We can find the pH of a buffer using H-H equation:

pH = pKa + log [A⁻] / [HA]

<em>Where [A⁻] is the molar concentration of the base, NH₃, and [HA] molar concentration of the acid, NH₄⁺. This molar concentration can be taken as the moles of each chemical</em>

<em />

First, we need to find pKa of NH₃ using Kb. Then, the moles of NH₃ and finally replace these values in H-H equation to solve moles of NH₄Cl we need to obtain the desire pH.

  • <em>pKa NH₃/NH₄⁺</em>

pKb = - log Kb

pKb = -log 1.8x10⁻⁵ = <em>4.74</em>

pKa = 14 - pKb

pKa = 14 - 4.74

pKa = 9.26

  • <em>Moles NH₃</em>

<em>2.00L ₓ (0.200mol NH₃ / L) = 0.400 moles NH₃</em>

  • <em>H-H equation:</em>

pH = pKa + log [NH₃] / [NH₄Cl]

8.20 = 9.26 + log [0.400 moles] / [NH₄Cl]

-1.06 =  log [0.400 moles] / [NH₄Cl]

0.0087 =  [0.400 moles] / [NH₄Cl]

[NH₄Cl] = 0.400 moles / 0.0087

[NH₄Cl] = 4.59 moles of NH₄Cl we need to add to original solution to obtain a pH of 8.20. In grams (Using molar mass NH₄Cl=53.491g/mol):

4.59 moles NH₄Cl ₓ (53.491g / mol) =

<h3>245.66g of NH₄Cl is the mass we need to add to obtain the desire pH</h3>

<em />

You might be interested in
Under which conditions are gases most soluble in water?
Volgvan

Hi,

Gases are most soluble in water under high pressure and low pressure.

6 0
3 years ago
How does the specific heat of water compare to the specific heat of concrete?
telo118 [61]
The specific heat of water is higher than the specific heat of concrete.
5 0
3 years ago
The student wants to test the conductivity of each solution. Prior to carrying out the investigation, the student needs to ident
puteri [66]

Answer:b

Explanation: the particles will soon dissolve which means that the particles are changing but the volume is staying the same and the concentration is changing

3 0
2 years ago
Read 2 more answers
Why do two oxygen atoms form a double covalent bond?
elena-s [515]

A lone oxygen atom has 6 electrons in its outer shell which is not very stable, whereas as full octet (8 outer shell electrons) is stable. In order to achieve this two oxygen atoms will share 4 electrons, each contributing 2 electrons. Since these electrons exist within the orbitals of both atoms, to oxygen atoms essentially achieve a full octet.

5 0
3 years ago
What are the 5 steps in nuclear production​
ira [324]

The first step is splitting the atoms. Then there are control rods that absorb free floating nerons that are a result of fission. Next they heat they water pipe. Finally when they heat the pipe and water it turns to steam and they use it to harness energy!

6 0
2 years ago
Other questions:
  • What is the correct Lewis structure for Acetylene C2H2?
    12·1 answer
  • The reaction where heat is added is called? removed?
    11·1 answer
  • Uestion 1
    10·1 answer
  • Two students were conducting an experiment. They have two blocks of different metals and wanted to identify them. They started b
    12·1 answer
  • Identify each type of titration curve. note that the analyte is stated first, followed by the titrant.
    14·1 answer
  • What are 6 types of energies except Potential and Kinetic energy.
    9·1 answer
  • @ What is the wavelength of a radio wave having a frequency of 3.75 X 107 Hz?
    11·1 answer
  • If it requires 75.0mL of 0.500M NaOH to neutralize 165.0 mL of an hcl solution what is the concentration of the hcl solution
    15·1 answer
  • What conditions would produce the highest pressure?​
    13·1 answer
  • How can you determine the products of a single or double displacement reaction?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!