Compound A has a solubility of 0.2 g/mL in toluene at toluene's boiling point and a solubility of 0.05 g/mL at 0 ºC. How much toluene would be necessary to recrystallize 3.2 g of A. What would be the maximum amount of A that could be recovered if the saturated solution was allowed to cool to 0 ºC. How much A would be recovered, if you accidentally used twice as much toluene as was necessary?

1) 16 mL of toluene is necessary to recrystallize 3.2 g of compound A

2) 2.4 g of A is the maximum amount that could be recovered.

3) 1.6 g of compound A  can be recovered if you accidentally use twice as much  toluene as was necessary

Explanation:

1)

The volume of the solvent ( toluene) =

=

= 16 mL

∴  16 mL of toluene is necessary to recrystallize 3.2 g of compound A

2)

The maximum amount    A that could be recovered if the saturated solution was allowed to cool to 0 ºC is determined by the difference of the starting amount and amount left in the solution at 0 ºC

i.e

maximum amount of A = 3.2 - ( 16 mL × 0.05 g/mL)

= 3.2 g - 0.8 g

= 2.4 g

∴  2.4 g of A is the maximum amount that could be recovered.

3)

Amount of A that would be  recovered, if you accidentally used twice as much toluene as was necessary is calculated as follows;

amount of A = 3.2g - (32 mL × 0.05 g/mL)

= 3.2 g - 1.6 g

= 1.6 g

Thus; 1.6 g of compound A  can be recovered if you accidentally use twice as much  toluene as was necessary

the electronic configuration of an atom with eight electrons is 1s²2s²2p⁴. the orbital diagrams are shown in the figure.

as per the hunds rule:

1. electrons tend to avoid being in the same orbital as per as practicable.

2. electrons in different orbitals of the same energy will have their spin parallel.

this can be illustrated from the multiplicity of the orbitals of the atom. as there are four electrons in the p orbital and p orbital has 3 sub-shells. the electrons can be fed in different ways as shown in the figure but the correct orbital diagram will be as per the hunds rule.

i believe the answer is true.