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
pav-90 [236]
3 years ago
5

1. Calculate the concentration of hydronium ion of both buffer solutions at their starting pHs. Calculate the moles of hydronium

ion present in 20.0 mL of each buffer. 2. A change of pH by 1 unit means a change in hydronium ion concentration by a factor of 10. Calculate the number of moles of NaOH that would theoretically be needed to decrease the moles of hydronium you calculated in
Chemistry
1 answer:
lilavasa [31]3 years ago
5 0

Answer:

This question is incomplete, here's the complete question:

1. Calculate the concentration of hydronium ion of both buffer solutions at their starting pHs. Calculate the moles of hydronium ion present in 20.0 mL of each buffer.

Buffer A

Mass of sodium acetate used: 0.3730 g

Actual ph of the buffer 5.27

volume of the buffer used in buffer capacity titration 20.0 mL

Concentration of standardized NaOH 0.100M

moles of Naoh needed to change the ph by 1 unit for the buffer 0.00095mol

the buffer capacity 0.0475 M

Buffer B

Mass of sodium acetate used 1.12 g

Actual pH of the buffer 5.34

Volume of the buffer used in buffer capacity titration 20.0 mL

Concentration if standardized NaOH 0.100 M

moles of Naoh needed to change the ph by 1 unit 0.0019 mol

the buffer capacity 0.095 M

2.) A change of pH by 1 unit means a change in hydronium ion concentration by a factor of 10. Calculate the number of moles of NaOH that would theoretically be needed to decrease the moles of hydronium you calculated in #1 by a factor of 10 for each buffer. Are there any differences between your experimental results and the theoretical calculation?

3.) which buffer had a higher buffer capacity? Why?

Explanation:

Formula,

moles = grams/molar mass

molarity = moles/L of solution

1. Buffer A

molarity of NaC2H3O2 = 0.3731 g/82.03 g/mol x 0.02 L = 0.23 M

molarity of HC2H3O2 = 0. 1 M

Initial pH

pH = pKa + log(base/acid)

= 4.74 + log(0.23/0.1)

= 5.10

pH = -log[H3O+]

[H3O+] = 7.91 x 10^-6 M

In 20 ml buffer,

moles of H3O+ = 7.91 x 10^-6 M x 0.02 L

= 1.58 x 10^-7 mol

Buffer B

molarity of NaC2H3O2 = 1.12 g/82.03 g/mol x 0.02 L = 0.68 M

molarity of HC2H3O2 = 0.3 M

Initial pH

pH = pKa + log(base/acid)

= 4.74 + log(0.68/0.3)

= 5.10

pH = -log[H3O+]

[H3O+] = 7.91 x 10^-6 M

In 20 ml buffer,

moles of H3O+ = 7.91 x 10^-6 M x 0.02 L

= 1.58 x 10^-7 mol

2. let x moles of NaOH is added,

Buffer A,

pH = 5.10

[H3O+] = 7.91 x 10^-6 M

new pH = 4.10

new [H3O+] = 7.91 x 10^-5 M

moles of NaOH to be added = (7.91 x 10^-5 - 7.91 x 10^-6) x 0.02 L

= 1.42 x 10^-6 mol

3. Buffer B with greater concentration of NaC2H3O2 and HC2H3O2 has higher buffer capacity as it resists pH change to a wider range due to addition of acid or base to the system as compared to low concentration of Buffer A

You might be interested in
Choose the predominant type of bonding as ionic, covalent, or metallic for the substance below.
nadya68 [22]
It is ionic bond because of Na valency and it is alkali metal and cl is non metal and it’s valency , they both share electron and make ionic bonding .
5 0
3 years ago
Read 2 more answers
What were the limitations of Newlands Law of Octaves.?<br><br> No spam ❌❌<br> or else (-_-メ)​
liubo4ka [24]

Answer:

The major limitations of Newlands' law of octaves were : (i) It was applicable to only lighter elements having atomic masses upto 40 u, i.e., upto calcium. After calcium, the first and the eighth element did not have similar properties

5 0
3 years ago
Read 2 more answers
Write a balanced equation for the double-replacement precipitation reaction described, using the smallest possible integer coeff
ahrayia [7]

Answer:

NH4Br + AgNO3 —> AgBr + NH4NO3

Explanation:

When ammonium bromide and silver(I) nitrate react, the following are obtained as shown below:

NH4Br(aq) + AgNO3(aq) —>

In solution, NH4Br(aq) and AgNO3(aq) will dissociate as follow:

NH4Br(aq) —> NH4+(aq) + Br-(aq)

AgNO3(aq) —> Ag+(aq) + NO3-(aq)

The double displacement reaction will occur as follow:

NH4+(aq) + Br-(aq) + Ag+(aq) + NO3-(aq) —> Ag+(aq) + Br-(aq) + NH4+(aq) + NO3-(aq)

NH4Br(aq) + AgNO3(aq) —> AgBr(s) + NH4NO3(aq)

6 0
3 years ago
Which of the following intermolecular forces is the strongest?
Tanzania [10]

Answer:

A. Hydrogen Bonding

Explanation:

6 0
3 years ago
Student A performed gravimetric analysis for sulfate in her unknown using the same procedures we did . Results of her three tria
soldi70 [24.7K]

Answer:

The answer is Sodium Sulfate = Na2SO4  

Explanation:

Molar mass of sulfate = 1 (S) + 4 (O) = 1 (32) + 4 (16) = 32 + 64 = 96  

Molar mass of sodium sulfate = 2 (23) + 96 = 46 + 96 = 142  

% of Sulfate = (96/142)*100 = 67.6%  

Percent mistake in Studen A,  

(I) % mistake = (67.6 - 68.6)/67.6 = 1.48  

(ii) % mistake = (67.6 - 66.2)/67.6 = 2.07  

(iii) % mistake = (67.6 - 67.1)/67.6 = 0.74  

For understudy B  

(I) % mistake = (67.6 - 66.7)/67.6 = 1.33  

(ii) % mistake = (67.6 - 66.6)/67.6 = 1.48  

(iii) % mistake = (67.6 - 66.5)/67.6 = 1.63  

Sutdent An is some how exact.  

Understudy B is exact however not precise.

8 0
3 years ago
Other questions:
  • What does criteria mean???​
    10·2 answers
  • What can be created with differential weathering
    8·1 answer
  • Compare the amount of carbon dioxide released in one year from burning coal to power 10, 65-watt incandescent bulbs with the amo
    7·1 answer
  • 1. In 1996 a meteor crashed into the Earth near Steelsville, Ontario. The resulting meteorite was found to contain 5,790 g of Mo
    14·1 answer
  • Pls help asap!!!!!!!
    11·1 answer
  • Ano ang scientific method​
    6·1 answer
  • What science govern in nanostructure?​
    11·2 answers
  • Industries use heterogeneous catalysts because they are _______
    5·1 answer
  • Determine the mass of the following samples (remember mass =&gt; grams)
    11·1 answer
  • Approximately 50% of our bone is chemically calcium phosphate, Ca3(PO4)2
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!