Answer:
d. 3 signals: a singlet, a doublet, and a septet
Explanation:
In this case, we can start with the structure of 
. When we draw the molecule we will obtain <u>2-methoxypropane</u> (see figure 1).
In 2-methoxypropane we will have three signals. The signal for the 
groups in the left, the 
and the in the right. Lets analyse each one:
-) in the right
In this carbon, we dont have any hydrogen as neighbors. Therfore we will have <u>singlet</u> signal in this carbon.
-)
In this case, we have 6 hydrogen neighbors ( the two methyl groups in the left). So, if we follow the <u>n + 1 rule</u> (where n is the amount of hydrogen neighbors):
For this carbon we will have a <u>septet</u>.
-) in the left
In this case we have only 1 hydrogen neighbor (the hydrogen in
). So, if we use the n+1 rule we will have:
We will have a doublet
With all this in mind the answer would be:
<u>d. 3 signals: a singlet, a doublet, and a septet
</u>
<u />
See figure 2 to further explanations
A .
1 mol of sodium na atoms -22.99
22.99 x 8 =183.92
Closest answer
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.
They will attract each other when brought close but when they touch the glass rod will become a negative charge and will repel each other
