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anastassius [24]
3 years ago
7

Which of the following statements is true when considering temperature during a recrystallization? More than one answer may be c

orrect. It is important that the sample is dissolved in just enough hot solvent. Ideally the hot solvent used will keep the impurities dissolved OR not dissolve them at all. Using ice to cool the sample will speed up the crystallization process so that large crystals will be formed. Enough cold solvent should be added to dissolve the sample BEFORE heating it past its boiling point.
Chemistry
1 answer:
Otrada [13]3 years ago
4 0

Answer:

The correct answer is:

<em>(1) It is important that the sample is dissolved in just enough hot solvent. </em>

Explanation:

The process of recrystallization is important to eliminate the impurities and to obtain better crystals of the solid. The solvent used to perform the recrystallization must have a high dissolution power of the substance to be recrystallized and a low dissolution power of the impurities. This is in order to eliminate most impurities. Furthermore, <em>It is important that the sample is dissolved in just enough hot solvent </em>because this should be easy to remove after the recrystallization and the crystal should form easily when the solution cools. Also, it is better to add the hot solvent to solubilize the crystals and keep the impurities insoluble, instead of adding the cold solvent and heating the solution. Additionally, the process of cooling the solution must be done slowly to obtain large and fewer crystals. A fast ice-cooling will form smaller crystals.

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+<br> c)<br> FeCl3 +<br> NH4OH<br> Fe(OH)3<br> NHACI
bixtya [17]

The question is incomplete, the complete question is:

Write the net ionic equation for the below chemical reaction:

(c): FeCl_3+3NH_4OH\rightarrow Fe(OH)_3+3NH_4CI

<u>Answer:</u> The net ionic equation is Fe^{3+}(aq)+3OH^{-}(aq)\rightarrow Fe(OH)_3(s)

<u>Explanation:</u>

Net ionic equation is defined as the equations in which spectator ions are not included.

Spectator ions are the ones that are present equally on the reactant and product sides. They do not participate in the reaction.

(c):

The balanced molecular equation is:

FeCl_3(aq)+3NH_4OH(aq)\rightarrow Fe(OH)_3(s)+3NH_4Cl(aq)

The complete ionic equation follows:

Fe^{3+}(aq)+3Cl^-(aq)+3NH_4^+(aq)+3OH^{-}(aq)\rightarrow Fe(OH)_3(s)+3NH_4^+(aq)+3Cl^-(aq)

As ammonium and chloride ions are present on both sides of the reaction. Thus, they are considered spectator ions.

The net ionic equation follows:

Fe^{3+}(aq)+3OH^{-}(aq)\rightarrow Fe(OH)_3(s)

5 0
3 years ago
What can happen if you have heated glass next to cool or cold water?
Effectus [21]
The class can break or if you put it in cold water it can cool down down fast.
6 0
3 years ago
Reason why chemistry is studied
mina [271]

Answer: Chemistry is the study of change. Various reasons why to study Chemistry is to appreciate the fundamentals of the world such as the composition of all living thing. We are made up of matter. The interaction of sub atomic particles in an atom to form a single being. Also to understand how certain chemicals are beneficial and harmful in our lives just by reading product labels.

Explanation:

3 0
3 years ago
Once formed, how are coordinate covalent bonds different from other covalent bonds?
-Dominant- [34]

Answer:

\boxed {\boxed {\sf {One \ atom \ donates \ both \ electrons \ in \ a \ pair}}}

Explanation:

A covalent bond involves the sharing of electrons to make the atoms more stable, and so they satisfy the Octet Rule (8 valence electrons).

Typically each atom contributes an electron to form an electron pair. This is a single bond. There are also double bonds (two pairs of electrons), triple bonds (three pairs of electrons), and coordinate covalent bonds.

Sometimes, to satisfy the Octet Rule and achieve stability, one atom contributes both of the electrons in an electron pair. This is different from other covalent bonds because usually each of the 2 atoms contributes an electron to make a pair.

4 0
3 years ago
Which of the
saul85 [17]

Answer:

During chemical reactions, matter is neither

created nor destroyed; it just changes form.

Explanation:

6 0
3 years ago
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