# organic chemistry

posted by Anonymous

How to find the volume of hot water required to dissolve the mass of acid, if we have 20g of benzoic acid contaminated with 0.4g of salicylic acid?
What is the mass of benzoic acid which participates when the solution is cooled to 20°C? Deduce.
What is the mass of salicylic acid which co-precipitated with the mass of benzoic acid?
What is the percentage of benzoic acid obtained after the recrystallisation?
Solubility (g/100ml) of BA at 20°C :0.29 and at 100°C:6.8
Solubility (g/100ml) of SA at 20°C:0.22 and at 100°C:6.67

1. DrBob222

When do these I ignore the water necessary to dissolve the impurity; often the minimum amount of H2O needed is just the amount to dissolve the major element and the impurity is dissolved in that same amount of water.
100 mL x (20g/6.67) = about 300 mL a 100 C.

How much will ppt at 20 C?
BA = 0.29 x (300/100) = about 0.9 lost.
SA = 0.22 x (300/100) = about 0.7 lost.
amount BA pptd 20-0.9 = ?
amount SA pptd 0.4-0.7 = 0

etc.

## Similar Questions

1. ### organic chemistry

breifly describe how you would separate a mixture of sand and benzoic acid(benzoic acid is soluble in hot water) to obtain pure benzoic acid
2. ### Chemistry

Enough water is added to 0.35 g of benzoic acid to make 1000 mL of solution. What is the pH?
3. ### Chemistry

You have 150 ml of a solution of benzoic acid in water estimated to contain about 5 g of acid. The distribution coefficient of benzoic acid in benzene and water is approx 10. Calculate the amount of acid that would be left in the water …
4. ### Organic Chemistry

An impure sample contains 0.95g of benzoic acid and 0.05 of salicylic acid. Solubilities in water of the two compounds are given in the following table. Solubility at 20 degrees (g/10mL) benzoic acid: 0.029 salicylic acid: 0.22 Solubility …
5. ### Organic Chemistry

An impure sample contains 0.95g of benzoic acid and 0.05 of salicylic acid. Solubilities in water of the two compounds are given in the following table. Solubility at 20 degrees (g/10mL) benzoic acid: 0.029 salicylic acid: 0.22 Solubility …
6. ### Chemistry

Assume the solubility of benzoic acid in ice-cold water is 1.70 g/L and the solubility of benzoic acid in hot water is 68.0 g/L. Calculate the minimum volume of water (in mL) needed to recrystallize 0.950 g of benzoic acid.
7. ### Chemistry

Assume the solubility of benzoic acid in ice-cold water is 1.70 g/L and the solubility of benzoic acid in hot water is 68.0 g/L. Calculate the minimum volume of water (in mL) needed to recrystallize 0.350 g of benzoic acid.
8. ### Organic Chemistry

If your carboxylic acid is benzoic acid, how many moles of benzoic acid are present in your sample (0.30g, and it is a mixture of three components of equal mass)?
9. ### chemistry

Given 20g of benzoic acid contaminated with 0.4g of salicytic acid. 1)Determine the volume of hot water required to dissolve the mass of acid. 2)Calculate the mass of benzoic acid which participates when the solution is cooled to 20°C. …
10. ### Chemistry

References Chapter 17: EOC Assume you dissolve 0.178 g of the weak acid benzoic acid, , in enough water to make mL of solution and then titrate the solution with 0.187 M . ( for benzoic acid = .) What was the pH of the original benzoic …

More Similar Questions