Identify the characteristics of a good recrystallization solvent. Select one or more: Is not an organic liquid with a low boiling point. Dissolves a chemical sample well at high temperatures. Does not dissolve a chemical sample well at high temperatures. Does not dissolve a chemical sample well at low temperatures. Dissolves a chemical sample well at low temperatures.

Answers

Answer 1

Answer:

Dissolves a chemical sample well at high temperatures.

Does not dissolve a chemical sample well at low temperatures.

Explanation:

Recrystallization is a purification technique that involves mixing of an impure solid compound with a hot solvent leading to a saturated solution. As this solution cools, the compound to be purified becomes less soluble in the solvent, and pure crystals appear from the solution as the solution cools.

A good recrystallization solvent should

Not dissolve the compound that we want to purify at room temperature Dissolve the compound completely only  at the solvent's boiling point Dissolve all the soluble impurities in the sample very well at room temperature.Have a fairly low boiling point such that its boiling point is lower than the melting point of the compound to be purified and evaporates easily when air-drying the sample.

Related Questions

1
Give two reasons that show sugar is a compound
2
What is the difference between carbon (charcoal and suga? Compra ad 1​

Answers


Sugar is compound because it gets compressed

A 2.26 M solution of KOH is prepared. Calculate the moles and mass of solute present in a 15.2-mL sample of this solution. The molar mass of KOH is 56.11 g/mol.

Answers

Answer:

0.0344 moles and 1.93g.

Explanation:

Molarity is defined as the ratio between moles of a solute (In this case, KOH), and the volume. With molarity and volume we can solve the moles of solute. With moles of solute we can find mass of the solute as follows:

Moles KOH:

15.2mL = 0.0152L * (2.26mol / L) = 0.0344moles

Mass KOH:

0.0344 moles * (56.11g/mol) = 1.93g of KOH

helpp pleasee.............​

Answers

Answer:

it's answer is lithium and boron.

Yea the answer is Lithium and boron

Decide which element probably forms a compound with hydrogen that has a chemical formula most and least similar to the chemical formula of the compound formed by hydrogen and sulfur.

Answers

Answer:

Most similar- oxygen

Least similar- sodium

Explanation:

The complete question is shown in the image attached.

Now let us consider all the options in the questions carefully. We do know that hydrogen forms  covalent bonds with sulphur. Two hydrogen atoms form form two polar covalent bonds with one sulphur atom. The molecule is bent owing to the presence of two lone pairs of electrons on the sulphur central atom.

Oxygen is in the same group as sulphur in the periodic table. The compound between hydrogen and sulphur is strikingly similar to the compound formed between sulphur and hydrogen due to chemical similarity of compounds of elements in the same group of the periodic table. Hence H2O bears the greatest similarity to H2S.

The bond between hydrogen and halogens is also polar covalent but less similar to the bond between sulphur and hydrogen.

Lastly, the bond between hydrogen and sodium is ionic and least similar to the bond between hydrogen and sulpur. We actually have in that compound, Na^+ H^-. Sodium transfers one electron to hydrogen as is implied in the ionic formula shown.

Hence the answer above.

Suppose a lab procedure calls for 0.75 L of a 0.25 M CaCl2 solution. How much of a 10.0 M stock solution do we dilute?

Where the diluted solution is #2 (the numerator)

Answers

Answer:

V₁ = 0.019 L

Explanation:

Given data:

Molarity of stock solution = 10.0 M

Volume of stock solution = ?

Molarity of CaCl₂ = 0.25 M

Volume of CaCl₂ = 0.75 L

Solution:

Formula:

V₁ = M₂V₂ / M₁

V₁ = 0.25 M × 0.75 L / 10.0 M

V₁ = 0.1875 M.L / 10.0 M

V₁ = 0.019 L

Fungus is an example of a/an-

A:tissue
B:cell type
C:organ
D:organism

Answers

Answer:

D.organism

Explanation:

A fungus from the kingdom fungi is an organism

Answer:

D. organism

......................

What type of compound is Sodium hydroxide?
A.acid
B.base
C.element
D.salt

Answers

The answer is B
b base

Answer: B: Base

Explanation: I took the test

Give the IUPAC name for each compound.

Answers

Answer:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

Explanation:

Hello!

In this case, according to the IUPAC rules for the listed alkyl halides, we first need to name the halogens (considering periodic order) then alkyl radicals and finally the parent chain; thus, the names are given below:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

e. 5-chloro-1-bromo-1,1,5-trimethyl-pentane (radicals are not clear).

Best regards!

How does knowing the reactants and products
help you classify a chemical reaction? Write a
short paragraph explaining.

Answers

Answer:

Here's the Sample Response: The reactants and products determine the type of chemical reaction. If there are more products than reactants, then it is a decomposition reaction. If there are more reactants than products, it is a synthesis reaction. If oxygen is a part of the reactant, it is a combustion reaction. If one ion replaces another, it is a single replacement reaction. If there are two compounds in a reactant where cations switch, it is a double replacement reaction.

Explanation:

If 4.55 moles of hydrogen were reacted with excess nitrogenin the equations N2 + 3 H2 = 2 NH3 and 48.7 g of ammonia product was recovered what would be the percent yield of the reaction?

Answers

Answer:

Percent yield = 94.5%

Explanation:

Given data:

Number of moles of hydrogen = 4.55 mol

Mass of ammonia recovered = 48.7 g

Percent yield of ammonia = ?

Solution:

Chemical equation:

N₂+ 3H₂    →       2NH₃

Now we will compare the moles of ammonia and hydrogen.

               H₂        :         NH₃

                3         :          2

                4.55   :         2/3×4.55 = 3.03 mol

Theoretical yield of ammonia:

Mass = number of moles × molar mass

Mass = 3.03 mol × 17 g/mol

Mass = 51.51 g

Percent yield:

Percent yield = ( actual yield / theoretical yield ) × 100

Percent yield = (48.7 g/ 51.51 g)  × 100

Percent yield = 0.945 × 100

Percent yield = 94.5%

How many electrons would Fluorine have to gain or lose to become stable?

Answers

Answer:

 is most likely to gain one electron to form an ion with a 1- charge.

The reaction where sodium (Na) reacts with water to produce hydrogen gas is a type of reaction.

Answers

Answer:

In what way and in what form does sodium react with water? A colourless solution is formed, consisting of strongly alkalic sodium hydroxide (caustic soda) and hydrogen gas. This is an exothermic reaction.

g Determine the oxidation state for each of the elements below. ... The oxidation state of ... phosphorus ... in ... phosphorous tribromide PBr3 ... is ... . The oxidation state of nitrogen in nitrogen gas N2 is . The oxidation state of arsenic in arsenic acid H3AsO4 is .

Answers

Answer:

- P in PBr3 is +3.

- N in N2 is 0.

- As in H3AsO4 is +5.

Explanation:

Hello!

In this case, since the determination of the oxidation states is performed by using the well-known charge balances, we can proceed as shown below:

- P in PBr3: Here, bromide ions have an oxidation state of -1, so we follow:

[tex]P^xBr_3^-\\\\x-3=0\\\\x=+3[/tex]

Thus, the oxidation state is +3.

- N in N2: Here, since nitrogen is bonding with nitrogen and it is neutral, we infer its oxidation state is 0.

- As in H3AsO4: Here, oxygen is -2 and hydrogen +1, so we follow:

[tex]H_3^+As^xO_4^{-2}\\\\3+x-8=0\\\\x=8-3\\\\x=5[/tex]

Thus, the oxidation state is +5.

Best regards!

how are series and parallel circuits the same?

Answers

In a series circuit, the sum of the voltages consumed by each individual resistance is equal to the source voltage. ... In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents flowing through each component

Why must the red blood cells and the solution in the beaker be isotonic?

Answers

If a cell is placed in an isotonic solution, there will be no net flow of water into or out of the cell, and the cell's volume will remain stable. If the solute concentration outside the cell is the same as inside the cell, and the solutes cannot cross the membrane, then that solution is isotonic to the cell.

What is the definition of climate?
1) An area's long term weather pattern
2)When large air masses of different density, moisture, and temperature mee
3)The state of the atmosphere at a given place and time
4)Large volume of air that has similar characteristics of temperature and water
vapor content

Answers

Answer:

1) An area's long term weather pattern

Explanation:

Climate is defined as the weather pattern in an area for the long term. Climate means the usual condition of the humidity, temperature, wind, rainfall, and atmospheric pressure in the surface area of Earth for the long term. Usually the time period for a climate in a region is taken over 30-years.

Weather is the state of the atmosphere and climate the long-term weather pattern of the area. For example: degree to which it is hot or cold is weather and expect snow in the Northeast in every January is climate.

Hence, the correct answer is "1) An area's long term weather pattern".

what is the volume of the rock? if the water rose from 50L to 70mL

Answers

20 I think that’s the volume of it because 50-70 is 20 so it must’ve been 20 volume that lifted the water to 70 ML

A mass m of water is at a temperature of 290K. The specific heat capacity of water is c. Ice, at its melting point, is added to the water to reduce the water temperature to the freezing point. The specific latent heat of fusion for ice is L. What is the minimum mass of ice that is required

Answers

Answer:

17 mc/L

Explanation:

We habe heat that is taken by the ice for it to melt to be equal to the heat given by water.

ML = mc(290K - 273K)

ML = mc 17

Then we divide through by L

M = 17 mc/L

Please note that 273k as we have used in thIs solution is the temperature at which we can have water to freeze

Therefore the minimum mass of required ice = 17 mc/L

Which lists important roles of coral reefs?
cleaning oil from oceans, protecting beaches, producing oxygen
producing oxygen, offering medical benefits to humans, supporting a variety of organisms
supporting a variety of organisms, cleaning oil from oceans, producing oxygen
offering medical benefits to humans, protecting beaches, supporting a variety of organisms

Answers

I believe the answer is C which is supporting a variety of organisms, cleaning oil from oceans, producing oxygen.

Answer:

D. offering medical benefits to humans, protecting beaches, supporting a variety of organisms

Explanation:

I took the test and put C and got it wrong and l went back to see what the correct answer as and it was D.

The compound cobalt(II) bromide is a strong electrolyte. Write the transformation that occurs when solid cobalt(II) bromide dissolved in water. Be sure to specify states such as (aq) or (s).

Answers

Answer and Explanation:

The chemical formula for cobalt(II) bromide is CoBr₂. As it is a strong electrolyte, it dissociates into ions when dissolved in water, according to the following chemical equation:

CoBr₂(s) → Co²⁺(aq) + 2 Br⁻(aq)

Thus, the compound CoBr₂ dissociates in water producing 1 mole of cobalt(II) ions (Co²⁺) and 2 moles of bromide ions (Br⁻) per mole of CoBr₂. The ions are dissolved in water, so they are in the aqueous state (aq).

What do you think went well last semester in your chemistry class?

Answers

This seems like more of a you thing, but give me brainliest anyways. >:D

I think I passed everything it’s going alright

8. As the temperature of a mixture increases, one part of the mixture may 2 points
melt while the other parts remain solid. *
True
Or
False

Answers

Answer:

It's false

Explanation:

Mixtures are always combinations of the same compounds that are at different states.

Find the volume, in Liters, of 2.5 x 1024 molecules of chlorine gas at STP.

Answers

Answer:

V = 93.0 L

Explanation:

Hello!

In this case, when computing the PVT properties for an ideal gas, we need to use the following equation:

[tex]PV=nRT[/tex]

In such a way, for 2.5 x 10²⁴ molecules of chlorine at STP (273.15 K and 1.00 atm) we first need the moles based on the Avogadro's number:

[tex]n = 2.5x10^{24}molec*\frac{1mol}{6.022x10^{23}molec} = 4.15mol[/tex]

Now, we solve for volume on the ideal gas equation to obtain:

[tex]V=\frac{nRT}{P}[/tex]

So we plug in and get:

[tex]V=\frac{4.15mol**0.08206\frac{atm*L}{mol*K}*273.15K}{1.00atm}\\\\V=93.0L[/tex]

Best regards!

What do tissues combine to form?

A. organisms

B. cells

C.organ systems

D. organs

Answers

Answer is D organs because cell forms tissues, tissues form organs and organs forms the organ system
D. Organs is correct
Biological hierarchy goes in this order:
Atoms form molecules, molecules form cells, cells form tissues, tissues form organs, organs form organ systems, organ systems form organisms, groups of the same organism is a population, different populations living together is a community, a physical environment of different communities is an ecosystem, a region of a specific ecosystem is a biome, and all the biomes together create the biosphere. :)

The number of electrons in 1.6 gram CH, is:​

Answers

Answer:

6.022 x 10²³ electrons

Explanation:

Oh gosh oh I thought had the wrong

(1132 CHCH2CH = CH2
12. Give the complete IUPAC name for each of the following compounds:
(a) (CH3)2CHF
(b) CH3CHCICHCICH3
(C)
CH3CHCH;
CH2CH3
(d) CH3 CH2 CH = CHCHZ
(e)
CH3CH2CH2CHBCH2CH3
CH2CH=CH2​

Answers

Answer:

Ok:

Explanation:

a) 2-fluoropropane

b) 2,3 dichlorobutane

c) pent-2-ene or 2 pentene (I assume the semicolon was a typo)

d) Same as c (I assume Z is a typo too)

e) non-1-ene or 1-nonene (I assume the B is a 2)

A 4.0g Glass was heated from 5°C to 45°C after absorbing 32 J of heat. What is the specific heat of the glass? 

Answers

Answer:

[tex]c=0.2\ J/g^{\circ} C[/tex]

Explanation:

Given that,

Mass of a glass, m = 4 g

Initial temperature, [tex]T_i=5^{\circ} C[/tex]

Final temperature, [tex]T_f=45^{\circ} C[/tex]

Heat absorbed, Q = 32 J

We need to find the specific heat of the glass. The formula for the heat absorbed is given by :

[tex]Q=mc\Delta T\\\\c=\dfrac{Q}{m\Delta T}\\\\c=\dfrac{32\ J}{4\ g\times (45-5)^{\circ} C}\\\\=0.2\ J/g^{\circ} C[/tex]

So, the required specific heat of the glass is [tex]0.2\ J/g^{\circ} C[/tex].

If one force on an object is 5 N upward and the other is 10 N downward what is the objects motion?

Answers

5 Newton’s down, because you subtract the 10-5 since their opposing forces so you would get 5 units downward as your net force

To solve this we must be knowing each and every concept related to force. Therefore, the  objects motion will be towards downward with a force of 5 N.

What is force?

A force is an outside entity that has the power to alter a body's state of rest or motion. It has a direction and a magnitude. The point where forces are applied is determined by the the force's direction as well as the application of the force.

Newton and dyne units are used to measure the force exerted on an item. When using the centimeter kilogram second system of units, force is measured in dynes (CGS unit). In the common international system of units, it is denoted by the letter Newton (N) (SI unit).

upward force=5 N

downward force= 10 N

total force acting on body=downward force-upward force

                                          = 10 N - 5 N

                                          =5 N downward force

The  objects motion will be towards downward with a force of 5 N.

Therefore, the  objects motion will be towards downward with a force of 5 N.

To learn more about force, here:

https://brainly.com/question/13014979

#SPJ5

what????????????????????????????????????????????????

Answers

Answer:

I

Explanation:

d

k

uhm....is there anything you need help with?

5. Selenium-83 has a half-life of 25.0 minutes. How many minutes would it take for a 10.0
mg sample to decay and have only 1.25 mg of it remain?

Answers

Explanation:

10.0mg / 1.25mg = 8

1/8 of the original mass => 3 half-life phases

Hence it will take 25.0 min * 3 = 75.0min.

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