ACSBR 17 Electric Cell - Assignment ANS

Anglo-Chinese School (Barker Road) A Methodist Institution Founded in 1886 CHEMISTRY DEPARTMENT OF SCIENCE Name: ANSWERS ( ) Class: SEC 4 SIMPLE ELECTRIC CELL – ASSIGNMENT ALEX LEE/2010 PAGE 1 OF 8 PURE Multiple-Choice Questions [20 Marks] TOTAL SCORE / 30 Write in your selected answer for the multiple-choice questions in the boxes provided. 1 2 3 4 5 6 7 8 9 10 B D D A B D D B A D 11 12 13 14 15 16 17 18 19 20 C D B A B D D B A A 1. An electric current flows in a copper wire as a result of A moving electrons and ions. C moving positive and negative ions. B moving electrons only. D moving protons only. 2. Below shows four simple electric cells, with the direction of electron flow indicated. Which of the following has the direction of electron flow wrongly indicated? A C B D 3. Electrical energy is produced by a simple cell as a result of A formation of covalent bonds between atoms. B formation of negative ions from atoms. C positive and negative ions coming together. D transfer of electrons from a more reactive to a less reactive element. Zn Fe electron flow Fe Mg electron flow Ca Zn electron flow Zn Cu electron flow

ALEX LEE/2010 PAGE 2 OF 8 4. A simple electric cell as set-up as shown. Which of the following pairs of metals would cause the bulb to light up the brightest? Electrode A Electrode B A calcium copper B calcium magnesium C copper silver D lead magnesium 5. A simple electric cell is shown below. Which of the following modifications to the set-up, each separately applied, will definitely cause the initial brightness of the bulb to increase? A replace the electrolyte with 1.2 M KCl instead B replace the magnesium electrode with calcium instead C replace the magnesium electrode with copper instead D replace the zinc electrode with calcium instead 6. Which of the following statements about the operation of a simple electric cell is false? A An example of a suitable electrolyte is dilute sulfuric acid. B Platinum may be used as one of the electrodes. C Reduction occurs at the cathode, and oxidation at the anode. D The electrode which is more reactive forms the positive electrode. 7. Which of the following statements about the operation of a simple electric cell is true? A A current is formed when positive charges flow from the cathode to the anode. B Electrons flow from the less reactive metal to the more reactive metal. C The more reactive metal has a tendency to increase in size. D The negative electrode oxidizes to form positive ions. A B K2SO4 (aq) 1.0 M KCl zinc magnesium

ALEX LEE/2010 PAGE 3 OF 8 8. Four cells were set up using aqueous sodium chloride as the electrolyte as shown in the diagrams. In each cell, only the underlined electrode dissolved. To establish the order of reactivity of the metals, it is necessary to set up two or more cell