January 2015 Chemistry Regents #76-78

Highlight to reveal answers and explanations

 

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

Question 51-53 Questions 54-55
 Questions 56-58 Questions 59-61 Questions 62-63 Questions 64-65 Questions 66-68 Questions 69-72  Questions 73-75  Questions 76-78  Questions 79-81 Questions 82-85

 

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Questions

 

  Base your answers to questions 76 through 78 on the information below.

A student makes an aqueous solution of lactic acid. A formula for one form of lactic acid is shown below.

The solution is placed in a sealed flask to be used in a laboratory investigation. The equation below represents the lactic acid equilibrium system in the flask.

76 Identify one organic functional group in a molecule of lactic acid. [1]

Answer-->-OH  or -COOH

77 Explain, in terms of the reaction rates, why the concentrations of the reactants and products remain constant in this system. [1]

Answer-->reaction rates are equal

78 Explain, in terms of LeChatelierís principle, why increasing the concentration of H+(aq) increases the concentration of lactic acid. [1]

Answer-->equilibrium shifts left

 

 

 
 

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

Question 51-53 Questions 54-55
 Questions 56-58 Questions 59-61 Questions 62-63 Questions 64-65 Questions 66-68 Questions 69-72  Questions 73-75  Questions 76-78  Questions 79-81 Questions 82-85

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