The solubility of Acetanilide in hot and cold water is:
Temperature.........Solubility in 100ml H20
100C....................5.5g
0C........................0.53g
What is the maximum recovery if 5.0g of acetanilide is recrystallized from 100mL of water?
My ans:
So this is what I understand, when heated, all of acetanilide is dissolved in water, this is then filtered and allowed to cool. Then it is kept in an ice bath, thus the temp is 0C and acetanilide is no longer soluble.
So the final max % recovery should be:
(5.0-0.53)/5.5 x 100%
And hopefully this is correct?
I think you are ok until the last step. At 100 C the entire 5.00 g is soluble. When filtered and placed in an ice bath, you can get all of it back except for 0.53 g (if you have used 100 mL H2O). So the amount recovered is 5.00 - 0.53 = 4.47 grams.
percent recovered is (4.47/5.00)*100 = ??
I have no idea why you divided by 5.5. You started with 5.00, not 5.50 grams.
Oh I just realized, that was a typo, I meant to divide it by the original mass of 5.0
getting 89.4%
Hi i have this exact question however this is the difference:
The solubility of Acetanilide in hot and cold water is:
Temperature.........Solubility in 100ml H20
100C....................5.5g
0C........................0.53g
What is the maximum recovery if 0.15g of acetanilide is recrystallized using a total of 3mL of hot water?
Looking at your answer, i know that my answer is wrong, Do i have to convert the amt of acetanilide used to increase the volume of water used to 100ml? Please tell me how to do this!! Thanks
Your understanding is correct, but the calculation for maximum recovery needs a small adjustment. To calculate the maximum recovery percentage, you need to consider the solubility of acetanilide at the lower temperature, which is 0.53g/100 mL of water.
The maximum recovery can be determined by comparing the amount of acetanilide dissolved in hot water with the amount that can remain dissolved in cold water after cooling.
First, find out how much acetanilide remains in hot water:
Initial amount of acetanilide = 5.0g
Solubility in 100 mL of hot water = 5.5g
Therefore, all of the 5.0g of acetanilide will dissolve in hot water.
Next, determine the amount of acetanilide that can remain dissolved in cold water after cooling:
Solubility in 100 mL of cold water = 0.53g
Now, subtract the solubility in cold water from the initial amount to find the maximum recovery:
Maximum recovery = (Initial amount - Solubility in cold water) / Initial amount x 100%
= (5.0g - 0.53g) / 5.0g x 100%
Calculating the above expression gives you the maximum recovery percentage.