The solubility data for compound A in 3 different solvents is given below Calcul
ID: 477547 • Letter: T
Question
The solubility data for compound A in 3 different solvents is given below Calculate the solubility in how and cold solvents for each, then predict whether a recrystallization in these solvents will be effective and explain your reasoning. solvent #1 0.5 g dissolves In 50 ml of hot solvent; 0.125 g recovered % recovery solubility in hot solvent (in g/L): solubility in cold solvent (in g/L): effectiveness: solvent #2. 0.5 g dissolves in 2 L of hot solvent: 0.250 g recovered % recovery solubility in hot solvent (in g/L): solubility in cold solvent (in g/L): effectiveness: solvent #3: 0.5 g dissolves in 60 mL of hot solvent; 0.475 g recovered % recovery: solubility in hot solvent (in g/L): solubility in cold solvent (in g/L): effectiveness:Explanation / Answer
(a)
0.50 g compound dissolves in 50mL of solvent. Amount of compound present in 1000mL = 0.50g *1000mL/50mL
= 10 gm
Solubility in hot solvent = 10gm/L
Amount recovered = 0.125 gm
Amount that remained dissolved = 0.5-0.125 = 0.375 gm
amount present in 1000mL = 0.375 *1000mL/50 mL = 7.5 gm
Solubility in cold solvent = 7.5 g/L
Effectiveness = poor
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(b)
0.50 g compound dissolves in 2L of solvent. Amount of compound present in 1L = 0.50g *1L/2L
= 0.25 g
Solubility in hot solvent = 0.25 g/L
Amount recovered = 0.250 gm
Amount that remained dissolved = 0.5-0.250 = 0.250 gm
amount present in 1000mL = 0.25 *1000mL/50 mL = 5 gm
Solubility in cold solvent = 5 g/L
effectiveness = medium
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0.50 g compound dissolves i60mL of solvent. Amount of compound present in 1000mL = 0.50g *1000mL/60mL
= 8.33 gm
Solubility in hot solvent = 8.33gm/L
Amount recovered = 0.475 gm
Amount that remained dissolved = 0.5-0.475 = 0.025 gm
amount present in 1000mL = 0.025 *1000mL/60 mL = 0.42 gm
Solubility in cold solvent = 0.42 g/L
Effectiveness : good. Recrystallization should be performed with this solvent.