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
MakcuM [25]
3 years ago
5

A chemistry graduate student is given 500. mL of a 0.20 M chloroacetic acid (HCH2ClCO2) solution. Chloroacetic acid is a weak ac

id with Ka= 1.3 x 10^-3. What mass of KCH2ClCO2 should the student dissolve in the HCH2ClCO2 solution to turn it into a buffer with pH = 3.01? You may assume that the volume of the solution doesn't change when the KCH2ClCO2 is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.
Chemistry
1 answer:
zhenek [66]3 years ago
3 0

Answer:

12 g of choloracetic acid

Explanation:

The buffer equilibrium is:

HCH₂ClCO₂ ⇄ CH₂ClCO₂⁻ + H⁺

pka= -log ka =

Ka: 1,3x10⁻³ = [CH₂ClCO₂⁻] [H⁺] / [HCH₂ClCO₂]

By Henderson-Hasselbalch equation:

pH = pka + log₁₀ [A⁻] / [HA]

3,01 = 2,89 + log₁₀ [A⁻] / [HA]

1,318 = [A⁻] / [HA]

As molar concentration of chloroacetic acid (HA) is 0,20M

[A⁻] = 0,26 mol/L

The volume is 500 mL ≡ 0,5 L

0,26mol/L × 0,5 L = 0,13 moles of chloroacetic acid. In grams:

0,13 mol × (94,5g / 1mol) = <em>12 g of choloracetic acid</em>

<em></em>

I hope it helps!

You might be interested in
In the reaction of aluminum bromide with ionized sodium bromide which compound is the Lewis acid
slavikrds [6]
1. What is a property of a base? You should N-O-T taste laboratory chemicals!!! I don't know why textbooks emphasize the taste of acids and bases. But that is the answer. 

<span>2. In the reaction of aluminum bromide with ionized sodium bromide, which compound is the Lewis acid? </span>
<span>What reaction??? </span>

<span>3 In a neutral solution the [H^+] is ____. </span>
<span>At 25C a solution is said to be neutral when the hydrogen ion concentration is 1.00x10^-7M. </span>

<span>4 With solutions of strong acids and strong bases, the word strong refer to ____. </span>
<span>The strength of electrolytes, including acids and bases, describes the degree to which the substance ionizes. Strong acids and bases ionize completely in water. </span>

<span>5 Which of the following pairs consists of a weak acid and a strong base? </span>
<span>a. sulfuric acid, sodium hydroxide == strong, strong </span>
<span>b.acetic acid, ammonia == weak, weak </span>
<span>c. acetic acid, sodium hydroxide* == weak, strong </span>
<span>d. nitric acid, calcium hydroxide == strong, strong </span>

<span>6. The ionization constant (K^a) of HF is 6.7 x 10^-4. Which of the following is true in a 0.1M solution of this acid? </span>
<span>a. [HF] is greater than [H^+][F^-].* == Yep </span>
<span>b. [HF] is less than [H^+][F^-]. == Nope </span>
<span>c. [HF] is equal to [H^+][F^-]. == if K=1 </span>
<span>d. [HF] is equal to [H^+][F^2-] == nonsense </span>

<span>7. The process of adding a known amount of solution of known concentration to determine the concentration of another solution is called ____. </span>
<span>The process of finding the concentration of an acid or base by neutralizing it with a known concentration of a known volume is a titration.</span>
8 0
3 years ago
Read 2 more answers
Draw the main lewis structure of nof. draw nonbonding electrons using the dot notation and bonding electrons as a bond.
navik [9.2K]

solution is attached below

6 0
3 years ago
Read 2 more answers
Help Thank you so much!
RideAnS [48]
Nitrogen Trichloride
4 0
3 years ago
Read 2 more answers
How many formula units are present in 25.0 mol of sodium chloride
bonufazy [111]
The way to work out formula units is to do the amount of moles (in this case 25) times by 6.022 x 10^23. so, the answer is 1.5055 x 10^25 formula units. hope this helps! (by the way ^ represents ‘to the power of’ because i cant get the smaller symbols on here)
7 0
3 years ago
Answer this please, that would be very helpful.
kramer

Hey, for #1, it's 1, 1, 1 because it's already balanced!

For #2, it's 1, 2, 1, 1 since the product side has 2 Cl's but left side only had 1.

8 0
3 years ago
Read 2 more answers
Other questions:
  • If the following weights have masses of 2, 4, 6 and 8 kg,
    5·1 answer
  • After substantial heating, 6.25 g of iron produced 18.00 g of a compound with chlorine. The empirical formula is:
    7·1 answer
  • What would be the greatest difference in using an open ceramic coffee mug rather than an insulated mug with a lid as a calorimet
    5·2 answers
  • Which is a Characteristic of a non elecrolyte​
    5·1 answer
  • Lead has a density of 11.3 g/mL. If you have 105 grams of lead,
    10·1 answer
  • At what temperature will aluminum have a resistivity that is three times the resistivity of tungsten at room temperature? (Assum
    11·1 answer
  • What hold's the nucleus together in an atom?
    9·1 answer
  • It takes 2,500,00 Liters of Helium to fill the Goodyear Blimp. How many moles is this?
    14·1 answer
  • Is a glass window good reflector of heat??
    8·2 answers
  • Why do you think most lampshades are made of translucent materials instead of transparent materials?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!