January 2010 Chemistry Regents #82-84

Highlight to reveal answers and explanations

 

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

Questions 51-52 Questions 53-55 Questions 56-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-68 Questions 69-71 Questions 72-75 Questions 76-78 Questions 79-81 Questions 82-84

 

Other Regents Exams

Questions

Base your answers to questions 82 through 84 on the information below.

The diagram below shows a system in which water is being decomposed into oxygen gas and hydrogen gas. Litmus is used as an indicator in the water. The litmus turns red in test tube 1 and blue in test tube 2.

The oxidation and reduction occurring in the test tubes are represented by the balanced equations below.

82 Identify the information in the diagram that indicates this system is an electrolytic cell. [1]

HIGHLIGHT TO SEE THE ANSWER

A battery is part of the cell and is providing energy that causes the reaction.

Electricity is used to operate the cell.

83 Determine the change in oxidation number of oxygen during the reaction in test tube 1. [1]

HIGHLIGHT TO SEE THE ANSWER

-2 to 0

84 Explain, in terms of the products formed in test tube 2, why litmus turns blue in test tube 2. [1]

HIGHLIGHT TO SEE THE ANSWER

Litmus turns blue when a sufficient amount of hydroxide ions are produced.

The reaction in test tube 2 produces OH- ions that make this solution basic. Litmus is blue in a basic solution.

Back to Regents Exams

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

Questions 51-52 Questions 53-55 Questions 56-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-68 Questions 69-71 Questions 72-75 Questions 76-78 Questions 79-81 Questions 82-84

 
Back to Regents Exams