C7H5NO3S 0.5894 g BaCl2 SO4^2- 0.5032 g BaSO4 mass percent

C7H5NO3S 0.5894 g BaCl2 SO4^2- 0.5032 g BaSO4 mass percent

 

 

Saccharin (C7H5NO3S) is sometimes dispensed in tablet form.

Ten tablets with a total mass of 0.5894 g were dissolved in water.

This solution was then oxidized to convert all the sulfur to sulfate ion,

which was precipitated by adding an excess of barium chloride solution.

The mass of BaSO4 obtained was 0.5032 g.

a) What is the average mass of saccharin per tablet?

b) What is the average mass percent of saccharin in the tablets?

 

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BaSO4의 몰질량 = 233.39 g/mol 이므로,

0.5032 g / (233.39 g/mol) = 0.002156 mol BaSO4

( 참고 https://ywpop.tistory.com/7738 )

 

 

 

SO4^2-(aq) + Ba^2+(aq) → BaSO4(s)

 

SO4^2- : BaSO4 = 1 : 1 계수비(= 몰수비) 이므로,

SO4^2-의 몰수 = 0.002156 mol

 

 

 

C7H5NO3S : SO4^2- = 1 : 1 계수비(= 몰수비) 이므로,

C7H5NO3S의 몰수 = 0.002156 mol

 

 

 

C7H5NO3S의 몰질량 = 183.18 g/mol 이므로,

0.002156 mol × (183.18 g/mol) = 0.3949 g C7H5NO3S

---> 정제 10개 속 사카린의 질량

 

 

 

0.3949 g / 10개 = 0.03949 g/개

= 39.49 mg/tablet

---> a) 정답

 

 

 

(0.3949 g / 0.5894 g) × 100 = 67.00% saccharin by mass

---> b) 정답

 

 

 

 

[키워드] 사카린 기준문서, 사카린 사전