Cocaine (C17H21O4N) is a natural substance found in coca leaves, which have been used for centuries as a local anesthetic and stimulant. Illegal cocaine arrives in the United States either as the pure compound or as the hydrochloride salt (C17H21O4NHCl). At 25oC, the salt is very soluble in water (2.50 kg/L), but cocaine is much less so (1.70 g/L). (a) What is the maximum amount (in g) of the salt that can dissolve in 50.0 mL of water? (b) If the solution in part (a) is treated with NaOH, the...

The maximum amount of the salt is 125 g C17H21O4NHCl.There are 65.6 L H2O need to dissolve additionally.

Q161CP - Chemistry: Molecular Nature Of Matter And Change

Q161CP

Question

Cocaine (C₁₇H₂₁O₄N) is a natural substance found in coca leaves, which have been used for centuries as a local anesthetic and stimulant. Illegal cocaine arrives in the United States either as the pure compound or as the hydrochloride salt (C₁₇H₂₁O₄NHCl). At 25^oC, the salt is very soluble in water (2.50 kg/L), but cocaine is much less so (1.70 g/L). (a) What is the maximum amount (in g) of the salt that can dissolve in 50.0 mL of water? (b) If the solution in part (a) is treated with NaOH, the salt is converted to cocaine. How much additional water (in L) is needed to dissolve it?

Step-by-Step Solution

Verified

Answer

The maximum amount of the salt is 125 g C₁₇H₂₁O₄NHCl.
There are 65.6 L H₂O need to dissolve additionally.

1Step 1: Calculating the maximum amount of salt

The mass of salt can be denoted as,

$M a s s o f s a l t = 50 \times 10^{- 3} L \times \frac{2.5 \times 10^{3} g}{L} = 125 g C_{17} H_{21} O_{4} N H C I$

2Step 2: Calculating the additional volume of water

The mass can be denoted as,

$M a s s o f C_{17} H_{21} O_{4} N = 125 g s a l t \times \frac{1 m o l s a l t}{339.8 g s a l t} \times \frac{1 m o l C_{17} H_{21} O_{4} N}{1 m o l s a l t} \times \frac{303.35 g C_{17} H_{21} O_{4} N}{1 m o l C_{17} H_{21} O_{4} N} M a s s o f C_{17} H_{21} O_{4} N = 111.59 g C_{17} H_{21} O_{4} N$

On multiply this mass by reciprocal of cocaine’s density to find final volume,

$V o l u m e o f s o l u t i o n = 11.59 g C_{17} H_{21} O_{4} N \times \frac{1 L}{1.7 g C_{17} H_{21} O_{4} N} = 65.64 L$

To find the additional volume of water added,

$A d d i t i o n a l v o l u m e o f w a t e r = 65.64 L - 50 \times 10^{- 3} L = 65.59 A d d i t i o n a l v o l u m e o f w a t e r \approx 65.6 L H_{2} O$

Q160CP

Q162CP

Other exercises in this chapter

Q159CP

Ethanol (CH3CH2OH), the intoxicant in alcoholic beverages, is also used to make other organic compounds. In concentrated sulfuric acid, ethanol forms diethyl et

View solution

Q160CP

When powdered zinc is heated with sulfur, a violent reaction occurs, and zinc sulfide forms:Zn(s)+S8(s)→ZnS(s)[unbalanced]Some of the reactants also combi

View solution

Q162CP

High-temperature superconducting oxides hold great promise in the utility, transportation, and computer industries. (a) One superconductor is La2-xSrxCuO4. Calc

View solution

Q158CP

Lead(II) chromate (PbCrO4) is used as the yellow pigment in traffic lanes, but is banned from house paint because of the risk of lead poisoning. It is produced

View solution