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
Anit [1.1K]
3 years ago
8

In Part III, the phenolphthalein indicator is used to monitor the equilibrium shifts of the ammonia/ammonium ion system. The phe

nolphthalein equilibrium established with water is Hph(aq)(colorless) + H2O (l) H3O+ (aq) + ph-(aq)(pink or red). You compared the color of the solutions in three test tubes that initially contained 3 mL of 0.1 M ammonium hydroxide and a few drops of phenolphthalein indicator. In the first test tube, you added 1 M NH4Cl dropwise. What color change was observed and what did this color change indicate about the shift in the phenolphthalein equilibrium? a. The solution turned a more intense pink or red color indicating that the phenolphthalein equilibrium shifted to the left, producing more of the pink or red colored Hph.
Chemistry
1 answer:
AnnZ [28]3 years ago
7 0

The pink color in the solution fades. Some of the colored indicator ion converts to the colorless indicator molecule.

<h3>Explanation</h3>

What's the initial color of the solution?

\text{NH}_4\text{Cl} is a salt soluble in water. \text{NH}_4\text{Cl} dissociates into ions completely when dissolved.

\text{NH}_4\text{Cl} \; (aq)\to {\text{NH}_4}^{+} \; (aq) +{\text{Cl}}^{-} \; (aq).

The first test tube used to contain \text{NH}_4\text{OH}. \text{NH}_4\text{OH} is a weak base that dissociates partially in water.

\text{NH}_4\text{OH} \; (aq) \rightleftharpoons {\text{NH}_4}^{+}  \;(aq)+ {\text{OH}}^{-} \; (aq).

There's also an equilibrium between \text{OH}^{-} and {\text{H}_3\text{O}}^{+} ions.

{\text{OH}}^{-}\;(aq) + {\text{H}_3\text{O}}^{+} \;(aq) \to 2\; \text{H}_2\text{O} \;(l).

\text{OH}^{-} ions from \text{NH}_4\text{OH} will shift the equilibrium between \text{OH}^{-} and {\text{H}_3\text{O}}^{+} to the right and reduce the amount of {\text{H}_3\text{O}}^{+} in the solution.

The indicator equilibrium will shift to the right to produce more {\text{H}_3\text{O}}^{+} ions along with the colored indicator ions. The solution will show a pink color.

What's the color of the solution after adding NH₄Cl?

Adding \text{NH}_4\text{Cl} will add to the concentration of {\text{NH}_4}^{+} ions in the solution. Some of the {\text{NH}_4}^{+} ions will combine with \text{OH}^{-} ions to produce \text{NH}_4\text{OH}.

The equilibrium between  \text{OH}^{-} and {\text{H}_3\text{O}}^{+} ions will shift to the left to produce more of both ions.

{\text{OH}}^{-}\;(aq) + {\text{H}_3\text{O}}^{+} \;(aq) \to 2\; \text{H}_2\text{O} \;(l)

The indicator equilibrium will shift to the left as the concentration of {\text{H}_3\text{O}}^{+} increases. There will be less colored ions and more colorless molecules in the test tube. The pink color will fade.

You might be interested in
What statement does not accurately describe the following equation? C6H12O6+---&gt;6H20+6CO2+energy A) oxygen is a react ant B)
STatiana [176]
The answer is B. The complete equation is C6H12O6 + 6O2 -->6H2O + 6CO2 + energy. So we can know that A and C and D is right. For B, the reaction release energy so it is exothermic reaction.
4 0
3 years ago
Read 2 more answers
Which of the following ions is in the lowest oxidation state?
bulgar [2K]

Answer:

I believe it is a hope this helps

5 0
3 years ago
Read 2 more answers
A theater director reinterprets a play by replacing its classical score with
cricket20 [7]

Answer:

The play will be more  appealing to a younger audience.

Explanation:

A younger audience will more likely appreciate current pop hits rather than classical score.

4 0
3 years ago
Read 2 more answers
What’s the bladder wall made up of?
AleksandrR [38]

Answer:

The bladder wall is made of many layers, including: Urothelium or transitional epithelium. This is the layer of cells that lines the inside of the kidneys, ureters, bladder, and urethra. Cells in this layer are called urothelial cells or transitional cells

Explanation:

8 0
3 years ago
A scientist obtains a set of measurements that are very close to one another. These can be said to be:
pickupchik [31]

Answer:

I believe this is a K-12 test question. If the answers below are what you have on your test . . .

- Precise

- Accurate

- Identical

- None of the above

Then the answer is <u>precise</u>.

3 0
3 years ago
Other questions:
  • Cooks use baking soda to make cakes light and fluffy. You might have used baking soda yourself. Baking soda is NaHCO3. A 0.1 M s
    8·1 answer
  • Could you use naoh to separate aspirin and acetaminophen by acid base extraction
    5·1 answer
  • A standard galvanic cell is constructed so that the overall cell reaction is as given below where M is an unknown metal. 2 Al3+(
    9·1 answer
  • How do you do today!?​
    7·2 answers
  • What is the Lewis structure for NbBr5
    14·1 answer
  • Based on the oxidation states of the atoms in this reaction, answer the questions. 4Fe(0) + 3O2(0) → 2Fe2(3+)O3(2-) How many ele
    10·1 answer
  • 38.2mm converted into cm
    8·1 answer
  • Of the following reactions occurring at 25ºC, which one involves the greatest increase in entropy?H2(g) + Cl2(g) = 2 HCl(g)H2O(s
    9·1 answer
  • What are two pieces of evidence that support the Big Bang Theory?
    7·1 answer
  • Identify the contents of the following mixtures. Select all that apply. Each circle is an atom. Different colors are used for di
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!