June 2009 Chemistry Regents #60-62

Highlight to reveal answers and explanations

Back to Regents Exams

 

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50 Questions 51-53 Questions 54-57 Questions 58-59 Questions 60-62 Questions 63-65 Questions 66-67 Questions 68-70 Questions 71-73 Questions 74-76 Questions 77-78 Questions 79-83

Questions

Base your answers to questions 60 through 62 on the information below. A voltaic cell with magnesium and copper electrodes is shown in the diagram below. The copper electrode has a mass of 15.0 grams. When the switch is closed, the reaction in the cell begins. The balanced ionic equation for the reaction in the cell is shown below the cell diagram. After several hours, the copper electrode is removed, rinsed with water, and dried. At this time, the mass of the copper electrode is greater than 15.0 grams. 60 State the direction of electron flow through the wire between the electrodes when the switch is closed. [1] HIGHLIGHT TO SEE THE ANSWER (NOTE Electrons Flows down Table J) The electrons flow from the Mg electrode to the Cu electrode. from anode to cathode 61 State the purpose of the salt bridge in this cell. [1] HIGHLIGHT TO SEE THE ANSWER ****CANNED RESPONSE "ION FLOW"*** The salt bridge allows ions to flow between the half-cells. preventing polarization 62 Explain, in terms of copper ions and copper atoms, why the mass of the copper electrode increases as the cell operates. Your response must include information about both copper ions and copper atoms. [1] HIGHLIGHT TO SEE THE ANSWER Copper ions from the solution are reduced to copper atoms at the electrode, increasing the mass of the electrode. ****Copper ions become copper atoms. The number of copper ions decreases, and the number of copper atoms increases. Next Questions

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50 Questions 51-53 Questions 54-57 Questions 58-59 Questions 60-62 Questions 63-65 Questions 66-67 Questions 68-70 Questions 71-73 Questions 74-76 Questions 77-78 Questions 79-83

Back to Regents Exams