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
igomit [66]
3 years ago
9

In a recrystallization (a technique that you will encounter later in the semester), a solid is dissolved in a solvent and later

the solvent is removed. if a mp of the sample is taken while the sample is still moist with solvent, what effect would that have on the mp of the sample?
Chemistry
1 answer:
grandymaker [24]3 years ago
7 0

In a recrystallization (a technique that you will encounter later in the semester), a solid is dissolved in a solvent and later the solvent is removed. if a mp of the sample is taken while the sample is still moist with solvent then melting point will not come out to be accurate, as solvent is still present in the compound and that results in the variation of the melting point as the residual solvent will serves as impurities , and due to the presence of these impurities, melting point vary and does not come to be accurate .

You might be interested in
The neutralization of a 0.455 g sample of recrystallized aspirin required 38.6 mL of 0.100 M NaOH solution. An additional 25.0 m
Schach [20]

Answer:

E) Two of the above statements are true.

Explanation:

The options are:

A) Before the solution is titrated with HCl it is pink and when the color changes from pink to colorless, the moles of H*(aq) equals the moles of OH"(aq) used in the hydrolysis of the neutralized aspirin. <em>TRUE. </em>Before the solution is titrated, there is an excess of NaOH (Basic solution, phenolphtalein is pink). Then, at equivalence point, after the addition of HCl, the pH is acidic and phenolphtalein is colorless.

B) Before the solution is titrated with HCl it is colorless and when the color changes from colorless to pink, the moles of H*(aq) equals the excess moles of OH(aq) added. <em>FALSE. </em>As was explained, before the titration, the solution is pink.

C) 25.0 mL of 0.100 M NaOH was added to the sample to hydrolyze the neutralized aspirin in the solution. The titration with HCl allows us to determine the moles of excess OH(aq) added. Once we determine the moles of excess OH(aq), we can determine moles of OH"(aq) used in the hydrolysis of the neutralized aspirin, which is equal to the moles of aspirin in the recrystallized aspirin. <em>TRUE. </em>Aspirin requires an excess of base (NaOH) for a complete dissolution (Hydrolysis). Then, we add H+ as HCl to know the excess moles of OH-. As we know the added moles of OH-, we can find the moles of OH that reacted = Moles of aspirin.  

D) We can determine the moles of aspirin in the recrystallized aspirin by titrating with the 0.100 M NaOH to the neutralization point. The purpose of the hydrolysis of the neutralized aspirin and the back-titration with the 0.100 M HCl is to confirm the moles of aspirin in the recrystallized aspirin. <em>FALSE. </em>NaOH can be added directly unyil neutralization point because, initially, aspirin can't be dissolved completely

E) Two of the above statements are true. <em>TRUE</em>

<em></em>

Right option is:

<h3>E) Two of the above statements are true.</h3>
3 0
3 years ago
Hydrogen is grouped with the alkali metals because it
loris [4]

Answer:

Hydrogen is placed above group in the periodic table because it has ns1 electron configuration like the alkali metals. However, it varies greatly from the alkali metals as it forms cations (H+) more reluctantly than the other alkali metals.

Explanation:

5 0
3 years ago
In the periodic table, a set of properties repeats from
jok3333 [9.3K]

in the periodic table, a set of properties repeats from row to row

3 0
3 years ago
Read 2 more answers
What makes PLA hydrophilic?
zavuch27 [327]
Because of its chemical structure.
7 0
2 years ago
List the compounds in decreasing boiling point order
tensa zangetsu [6.8K]
Need more info, give some numbers or a picture of the problem
7 0
4 years ago
Other questions:
  • All of the sentences below are grammatically correct EXCEPT one, which contains a comma splice. Select the sentence that is NOT
    9·2 answers
  • If 42.7 mL of a 0.208 M HCl solution is needed to neutralize a solution of Ca(OH)2, how many grams of Ca(OH)2 must be in the sol
    9·1 answer
  • Use the image to rank the colors from the color that will refract the least to the color that will refract the most.
    14·2 answers
  • A Saint Bernard and a Chihuahua are of the same species but look very different. It is possible to breed the two and get a puppy
    9·1 answer
  • An organism that contains chloroplasts is able to produce food by the process of
    8·1 answer
  • 7.0
    8·1 answer
  • A pencil has a density of .655 g/ml. It has a mass of 3.5g. What is its volume
    8·1 answer
  • According to Dalton's atomic theory
    6·1 answer
  • If you have 50 g of iron (Fe) and of oxygen (O2), which one contains more particles?
    10·1 answer
  • FeS + ….HNO3 …….……..+ ….H2SO4 + ….NO + ……….
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!