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nevsk [136]
2 years ago
15

What should be the temperature of the solvent before adding it to the sample to be recrystallized?

Chemistry
1 answer:
Serhud [2]2 years ago
3 0

Answer:

Near the boiling point of the solvent

Explanation:

The process of recrystallization is hinged on the fact that the amount of solute that can be dissolved by a solvent increases with temperature. The process involves creation of a solution by dissolving a solute in a solvent at or near its boiling point.  At the boiling point of the solvent, the solute has a greater solubility in the solvent; not much volume of  the hot solvent is required to dissolve the solute.

Before the solution is later cooled, you can now filter out insoluble impurities from the hot solvent. The quantity of the original solute drops appreciably because impurities have been removed. At this lower temperature, the solution becomes saturated and the solute can no longer be held in solution hence it forms pure crystals of solute, which can be recovered.

Recrystallization must be carried out using the proper solvent. The solute must be relatively insoluble in the solvent at room temperature but more soluble in the solvent at elevated temperature.

You might be interested in
How many moles of Manganese there in are 5.76 x 10(15) atoms of Mn?
aksik [14]

Answer:

1. 9.57 × 10^-9 moles.

2. 7.38mol

Explanation:

1.) To find the number of moles there are in the number of particles in an atom, we divide the number of particles (nA) by Avagadro's constant (6.02 × 10^23)

Hence, to find the number of moles (n) of Manganese (Mn), we say:

5.76 x 10^15 atoms ÷ 6.02 × 10^23

5.76/6.02 × 10^(15-23)

= 0.957 × 10^-8

= 9.57 × 10^-9 moles.

2.) Mole = mass/molar mass

Molar mass of sodium chloride (NaCl) = 23 + 35.5

= 58.5g/mol

mole = 431.6 g ÷ 58.5g/mol

mole = 7.38mol

7 0
2 years ago
What change in volume results if 50 mL of gas is cooled from 30 C to 4 C
11111nata11111 [884]

The relation between the volume of the gas and the temperature is established by Charles's law. With a decrease in the temperature, the volume decreases by 45.7 mL. Thus, option c is correct.

<h3>What is Charle's law?</h3>

Charle's law states the direct relation present between the temperature and the volume of the gas. The law is given as:

V₁ ÷ T₁ = V₂ ÷ T₂

Given,

V₁ = 50 mL

T₁ = 303.15 K

T₂ = 277.15 K

Substituting the value the final volume is calculated as:

50 ÷ 303.15 = V₂ ÷ 277.15

V₂ = (50 × 277.15) ÷ 303.15

= 45.71 mL

Therefore, option c. 45.7 mL is the final volume.

Learn more about Charles law here:

brainly.com/question/16927784

#SPJ1

5 0
2 years ago
The Thompson analogy titled "The Carpet-Seed Children Analogy" attempts to deal with the issue of failed ____________________(A)
vazorg [7]

Answer: (D) contraception

Explanation:

8 0
3 years ago
A sample of magnesium is burned in oxygen to form magnesium oxide. What mass of oxygen is consumed if 74.62 g magnesium oxide is
lana [24]
74.62 g of magnesium oxide is formed from 45.00 g magnesium so 74.62-45.00= 29.62 g of oxygen is consumed or in other words a new compound is formed in the burning of magnesium in oxygen with a heavier mass than the pure magnesium.
3 0
2 years ago
Scientists often work on projects for a long time and fail to see sources of error in their research. Which process allows an ou
prohojiy [21]

Answer:

The correct approach is Option B (Peer Review).

Explanation:

  • Rather made reference to someone as a scientific peer-review, it encourages the specialist who has not been essential to the study team to analyze the study objectively and pointed out everyone's mistakes. It serves as major self-regulation for scholars and aims to make the publishing process somewhat credible. Hence, the solution to this issue is Peer Examination.
  • Funding organizations rarely have the capabilities to recognize out mistakes, whereas definitive analysis is a method of study that helps to make a definitive statement. The gathering of data is simply a process of scientific study.

Other approaches do not apply to the example mentioned. Although the one mentioned is right.

4 0
3 years ago
Read 2 more answers
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