Suppose you had a mixture consisting of 20.0 g of compound A and 20.0 g of compound B dissolved in 100.0 mL of water at 95 degrees C. Suppose further that only 1.00 g of A are soluble in 100.0 mL of water at 5 degrees C but 15.0 g of B are soluble in 100.0 mL of water at 5 degrees C. What is the mass ratio of A to B in the 95 degree C mixture before recrystallization?

Question

Suppose you had a mixture consisting of 20.0 g of compound A and 20.0 g of compound B dissolved in 100.0 mL of water at 95 degrees C. Suppose further that only 1.00 g of A are soluble in 100.0 mL of water at 5 degrees C but 15.0 g of B are soluble in 100.0 mL of water at 5 degrees C. What is the mass ratio of A to B in the 95 degree C mixture before recrystallization?

Answer 1

Am I missing something? 20.0 g A and 20.0 g B @ 95C is a 1:1 ratio A/B. It appears to me that everything after the first sentence is superfluous information.

Answer 2

To determine the mass ratio of A to B in the 95 degrees C mixture before recrystallization, we need to compare the amount of A and B that can be dissolved in 100.0 mL of water at 95 degrees C.

Given that 1.00 g of A is soluble in 100.0 mL of water at 5 degrees C, we can assume that the solubility of A at 95 degrees C is higher than at 5 degrees C. Therefore, we can assume that all 20.0 g of A are soluble in 100.0 mL of water at 95 degrees C.

Similarly, given that 15.0 g of B is soluble in 100.0 mL of water at 5 degrees C, we can assume that the solubility of B at 95 degrees C is also higher than at 5 degrees C. However, we don't know the exact solubility of B at 95 degrees C.

To calculate the mass ratio of A to B, we need to determine the amount of B that is soluble at 95 degrees C. We can set up a proportion based on the known solubility values:

1.00 g of A is soluble in 100.0 mL of water at 5 degrees C
15.0 g of B is soluble in 100.0 mL of water at 5 degrees C

x g of B is soluble in 100.0 mL of water at 95 degrees C

Using the proportion, we can solve for the value of x:

1.00 g / 15.0 g = 100.0 mL / x

Cross-multiplying and solving for x:

x = (15.0 g * 100.0 mL) / 1.00 g
x = 1500.0 g mL

Therefore, 1500.0 g of B are soluble in 100.0 mL of water at 95 degrees C.

Now, we can calculate the mass ratio of A to B in the 95 degrees C mixture before recrystallization:

Mass ratio = mass of A / mass of B
Mass ratio = 20.0 g / 1500.0 g
Mass ratio = 0.0133

So, the mass ratio of A to B in the 95 degrees C mixture before recrystallization is approximately 0.0133.

Am I missing something? 20.0 g A and 20.0 g B @ 95C is a 1:1 ratio A/B. It appears to me that everything after the first sentence is superfluous information.

So simple

To determine the mass ratio of A to B in the 95 degrees C mixture before recrystallization, we need to compare the amount of A and B that can be dissolved in 100.0 mL of water at 95 degrees C.