August 2009 Chemistry Regents #65-67

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Questions

Base your answers to questions 65 through 67 on the information below.

 

A student used blue litmus paper and phenolphthalein paper as indicators to test the pH of distilled water and five aqueous household solutions. Then the student used a pH meter to measure the pH of the distilled water and each solution. The results of the student’s work are recorded in the table below.

65 Identify the liquid tested that has the lowest hydronium ion concentration. [1]

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household ammonia  or NH3(aq)

(The base, highest pH)

66 Explain, in terms of the pH range for color change on Reference Table M, why litmus is not appropriate to differentiate the acidity levels of tomato juice and vinegar. [1]

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Litmus is red for all pH values below 5.5.

67 Based on the measured pH values, identify the liquid tested that is 10 times more acidic than vinegar. [1]

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lemon juice

There is one zero in 10, so the pH is more acidic (a lower pH) by 1 pH unit.

Next Questions

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

Questions 51-55 Questions56-58 Questions 59-63 Question 64 Questions 65-67 Questions 68-72 Questions 73-76 Questions 77-79 Questions 80-81

 
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