June 2015 Chemistry Regents #73-75

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Question 73-75

 

 

Base your answers to questions 73 through 75 on the information below and on your knowledge of chemistry.

Rubbing alchol sold in stores is aqueous 2-propanol, CH3CHOHCH3(aq). Rubbing alcohol is availible in concentrations of 70.0% and 91% 2-propanol by volume.

To make 100. mL of 70.% aqueous 2-propanol, 70.mL of 2-propanol is dilute with enough water to produce a total volume of 100.mL. In a laboratory investigation, a student is given a 132mL sample of 91% aqueous 2-propanol to separate using the process of distillation.

73 State evidence that indicates the proportions of the components in rubbing alcohol can vary.

Answer--> There are 70.% and 91% solutions.

74 Identify the property of the components that make it possible to use distillation to separate the 2-propanol from water.

Answer--> Boiling points  (IMFs..OK)

75 Determine the volume of 2-propanol in the 132-mL sample.

Answer--> 120mL

Work not necessary....132mL x 0.91=120 mL

on to Questions 76-79

 

Questions 1-5 Questions 6-10 Questions 11-15 Questions 16-20 Questions 21-25 Questions 26-30 Questions 31-35 Questions 36-40 Questions 41-45 Questions 46-50

Questions 51-53 Questions 54-56 Questions 57-59 Questions 60-61 Questions 62-65 Questions 66-68 Questions 69-72 Questions 73-75  Questions 76-79  Questions 80-82  Questions 83-85

 

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