[portugal]

In the context of a unknown compound sample being recrystalised then a small portion of that dried in a oven. The questions says "calculate the yield of dry product of your entire sample" based on your measurements.

So would that mean dried weight/smal recrystalised sample or dried weight/ entire recrystallised or even dried weight/ original sample before recrystallisation???

[ARGOS++]

Dear Portugal;

Simply as it says:

The questions says "calculate the yield of dry product of your entire sample" based on your measurements.

Or with other words: Calculate the yield as if you would have done the procedure with the “whole”/all your Product.

Good Luck!
                    ARGOS⁺⁺

[portugal]

could you explain that better to me, what does it mean by with all your product?? i get mass of dried unknown after recrystalisation so whats the rest of product??

[ARGOS++]

Dear Portugal;

Maybe to do it in “A Picture” is more helpful:

Let’s say you started your Recrystallisation with 327.0 g (= A grams), and after Filtration of your Crystals you weighted them and got 371.0 g (= B g).
Now to get a fast answer for your boss you only dry 5.0 grams (= w g) and after half one hour  you weight again and result in 3.8 g (= d g).
What’s now your yield of the Recrystallisation process?

From drying you will get:     100.0 % * 3.8g     /    5.0 g =    76.0  %,    and
from wet Recrystallisation:  100.0 % * 371.0 g / 327.0 g =  113.46 %.

So the yield of your Recrystallisation will result in:  76.0 * 113.46 % =  86.2 %.
That’s all!
(Of course! You can do it in only one calculation step:  yield = 100.0 % * B g / ………)
(wet  = solvent wet.)

Good Luck!
                    ARGOS⁺⁺