Practice Set PDF

1. What would be the stoichiometric molar ratio of 𝑆𝑛𝑂2 /𝑁𝑂 3− given the unbalanced redox reaction: 𝑆𝑛 + 𝑁𝑂3− → 𝑆𝑛𝑂2 + 𝑁𝑂2 ? a. 4/2 c. 4/1 b. 2/1 d. 1/4 2. How many electrons were involved in the redox reaction giv...

1. What would be the stoichiometric molar ratio of 𝑆𝑛𝑂2 /𝑁𝑂 3− given the unbalanced redox reaction: 𝑆𝑛 + 𝑁𝑂3− → 𝑆𝑛𝑂2 + 𝑁𝑂2 ? a. 4/2 c. 4/1 b. 2/1 d. 1/4 2. How many electrons were involved in the redox reaction given below? 𝐶𝑟2 𝑂7 2− + 𝑆𝑂3 2− → 𝐶𝑟 3+ + 𝑆𝑂4 2− a. 6 c. 2 b. 3 d. 12 3. A cell that generates electricity due to spontaneous processes in the cell making a non- spontaneous process occur.? a. galvanic cell c. electrochemical cell b. electrolytic cell d. electrochemical device 4. Which of the following information is considered to be TRUE about electrolytic cell? 𝑜 a. requires energy to function c. has a positive 𝐸𝑐𝑒𝑙𝑙 b. spontaneous process is observed d. produces energy 5. Which part of the electrochemical cell experiences oxidation? a. Anode c. Salt Bridge b. Cathode d. Electrolyte in Anode 6. Given the reaction below: 𝐴𝑢3+ (𝑎𝑞) + 𝐵𝑟 − (𝑎𝑞) → 𝐴𝑢(𝑠) + 𝐵𝑟2 (𝑔) 𝐴𝑢3+ (𝑎𝑞) + 3𝑒 − → 𝐴𝑢(𝑠) 𝐸 0 = 1.50 𝑉 𝐵𝑟2 (𝑎𝑞) + 2𝑒 − → 2𝐵𝑟 − (𝑎𝑞) 𝐸 0 = 1.09 𝑉 𝑜 What is the resulting standard cell potential (𝐸𝑐𝑒𝑙𝑙 ) and its spontaneity? 𝑜 𝑜 a. 𝐸𝑐𝑒𝑙𝑙 = 0.41 V, nonspontaneous c. 𝐸𝑐𝑒𝑙𝑙 = 2.59 V, nonspontaneous 𝑜 𝑜 b. 𝐸𝑐𝑒𝑙𝑙 = 0.41 V, spontaneous d. 𝐸𝑐𝑒𝑙𝑙 = 2.59 V, spontaneous 7. Which is NOT TRUE about the reaction below? 𝑁𝑎 + (𝑎𝑞) + 𝐴𝑔(𝑠) → 𝑁𝑎(𝑠) + 𝐴𝑔+ (𝑠) 𝐴𝑔+ (𝑎𝑞) + 𝑒 − → 𝐴𝑔(𝑠) 𝐸 0 = +0.80 𝑉 𝑁𝑎 + (𝑎𝑞) + 𝑒 − → 𝑁𝑎(𝑠) 𝐸 0 = −2.71 𝑉 𝑜 a. 𝐸𝑐𝑒𝑙𝑙 is negative c. The reaction is non spontaneous b. The reaction occurs in a galvanic cell d. The reaction requires electrical energy _- to occur 9-10: Refer to the table. 8. Among the given combination of electrochemical species will react spontaneously? I. Fe3+ and Ag II. Au3+ and Fe2+ III. Hg2+ and Cr IV. Ag and Cu2+ V. Cu2+ and Na a. All the reaction will occur spontaneously c. II, III, V b. II and IV d. I, IV, V 9. Which of the following reactions are not possible to occur in a galvanic cell? a. 𝐶𝑢2+ + 2𝐴𝑔 → 2𝐴𝑔+ + 𝐶𝑢 c. 𝐴𝑢3+ + 𝐶𝑟 → 𝐶𝑟 3+ + 𝐴𝑢 b. 𝐶𝑟 3+ + 3𝑁𝑎 → 3𝑁𝑎 + + 𝐶𝑟 d. 𝐹𝑒 3+ + 𝐶𝑢 + → 𝐹𝑒 2+ + 𝐶𝑢2+ 10. For the reaction: 𝐶𝑢2+ + 𝑍𝑛 → 𝑍𝑛2+ + 𝐶𝑢, 𝐶𝑢2+ + 2𝑒 − → 𝐶𝑢 𝐸 0 = +0.34 𝑉 𝑍𝑛+ + 2𝑒 − → 𝑍𝑛 𝐸 0 = −0.76 𝑉 Calculate the free energy and predict its spontaneity. a. -214x103 kJ/mol, nonspontaneous c. 214x103 J/mol, nonspontaneous b. -214 kJ/mol, spontaneous d. 214 kJ/mol, spontaneous 11. Given the reaction: 𝐴𝑢3+ (𝑎𝑞) + 𝐵𝑟 − (𝑎𝑞) → 𝐴𝑢(𝑠) + 𝐵𝑟2 (𝑔) 𝐴𝑢3+ (𝑎𝑞) + 3𝑒 − → 𝐴𝑢(𝑠) 𝐸 0 = 1.50 𝑉 𝐵𝑟2 (𝑎𝑞) + 2𝑒 − → 2𝐵𝑟 − (𝑎𝑞) 𝐸 0 = 1.09 𝑉 What will be the equilibrium constant of the reaction? a. 8.48 x 107 c. 6.10 x 1020 b. 7.19 x 1013 d. 3.72 x 1041 12. Referring to the redox reaction below: 𝐴𝑔+ (𝑎𝑞) + 𝑁𝑎(𝑠) → 𝐴𝑔(𝑠) + 𝑁𝑎 + (𝑠)  𝐴𝑔+ (𝑎𝑞) + 𝑒 − → 𝐴𝑔(𝑠) 𝐸 0 = +0.80 𝑉 𝑁𝑎 + (𝑎𝑞) + 𝑒 − → 𝑁𝑎(𝑠) 𝐸 0 = −2.71 𝑉 What would be the Ecell if [Ag+]=2.7M and [Na+]=1.2M? a. 3.51 V c. 3.49 V b. 3.53 V d. -1.89 V 13. What battery has 6 set of cells submerged in a sulfuric acid electrolyte. It is rechargeable and is commonly used in automobiles? a. Fuel Cell c. Lithium Battery b. Lead Storage Battery d. Mercury Battery 14. Which statement is TRUE about a Mercury Battery? a. There is no changes in its electrolyte c. The voltage it produces is 1.5 V composition during operation b. Its electrolyte consists of ammonium d. The most common is the Leclanché cell chloride and zinc chloride 15. It is the deterioration process of a metal through an electrochemical process. a. Passivation c. Redox reaction b. Reduction d. Corrosion 16. An electrochemical cell that requires electrical energy and convert it to chemical energy to make a nonspontaneous process to occur a. Galvanic cell c. Electrochemical cell b. Electrolytic cell d. Voltic cell 17. For the reaction: 𝐹𝑒 3+ (𝑎𝑞) + 𝐴𝑔(𝑠) → 𝐹𝑒 2+ (𝑎𝑞) + 𝐴𝑔+ (𝑎𝑞) 𝐴𝑔+ (𝑎𝑞) + 𝑒 − → 𝐴𝑔(𝑠) 𝐸 0 = +0.80 𝑉 𝐹𝑒 3+ (𝑎𝑞) + 𝑒 − → 𝐹𝑒 2+ (𝑎𝑞) 𝐸 0 = +0.77 𝑉 𝑜 What is the Standard Cell Potential (𝐸𝑐𝑒𝑙𝑙 ) and predict whether it would occur in an electrolytic cell? 𝑜 𝑜 a. 𝐸𝑐𝑒𝑙𝑙 = 1.57 V, yes c. 𝐸𝑐𝑒𝑙𝑙 = -0.03 V, yes 𝑜 𝑜 b. 𝐸𝑐𝑒𝑙𝑙 = 1.57 V, no d. 𝐸𝑐𝑒𝑙𝑙 = -0.03V, no 18. Copper metal (63.546 g/mol) is purified by electrolysis. How much copper metal (in grams) could be produced from copper (II) oxide by applying a current of 10.0 A at the appropriate negative potential for 12.0 hours? Hint: F=96485 C/mol  a. 284 g c. 28.4 g b. 142 g d. 14.2 g 19. How long would it take to electroplate a flute with 28.3 g of silver (107.90 g/mol) at a constant current of 2.0 amps using AgNO3? a. 844 min c. 105 min b. 422 min d. 211 min 20. If in using a lead-acid battery to start a car, 1.00 gram of Pb (207.2 g/mol) is consumed on the anode, how long will it take to recharge the battery, using a current of 0.500 amperes to turn the PbSO4 that was produced back into Pb? a. 62 min c. 31.0 min b. 124 min d. 15.5 min 21. Which points in this phase diagram represent conditions of temperature and pressure where liquid will be present? a. a, b, and g only c. a, c, d, and g only b. a, c, d, and f only d. c, d, e, and g only 26-27. Refer to the phase diagram, 22. At which point does L phase present? a. 1, 2, 3, and 4, only c. 4 and only b. 1 only d. 2, 3, 4, and 5 only 23. At which point does the phase β present? a. 1, 2, 3, and 4, only c. 4 and only b. 1 only d. 2, 3, 4, and 5 only 24. Which of the images of chemical structure are considered to be an amorphous solid? a. c. b. d. 25. What unit cell has a total of 4 atoms in it? a. FCC c. Simple Cubic b. BCC d. None of the choices 26. Crystal lattices are identified based on the length of each of the side of its unit cell, as well as the angle between ach side. What crystal lattice is being described by sides having no equal length, but all the angles between each side are all 90 o? a. Triclinic c. Orthorhombic b. Cubic d. Tetragonal 27. Iron crystallizes in a body-centered cubic cell. Its density is 7.874 g/cm 3 (MM= 55.845 g/mol). Calculate the atomic radius of iron. Hint: NA= 6.022x1023 a. 156 pm c. 98 pm b. 124 pm d. 142 pm 28. Identify the type of unit cell of a gold crystal having a density of 12.64 g/cm3 and an edge length of the 4.695x10-8 cm. Hint: MM=196.967 g/mol, NA= 6.022x1023 a. FCC c. Simple Cubic b. BCC d. None of the choices 29. Bragg’s Law is particularly used in what process? a. X-ray scan c. X-ray crystallography b. Gamma-ray production d. X-ray production 30. If the angle of incidence is 30°, then the wavelength for first-order spectrum is equal to __________. a. d/2 c. d/3 b. d d. 2d 31. In Band Theory, what term describes the range of allowed energy levels that electrons can occupy in a solid material? a. Energy Barrier c. Energy Junction b. Energy Zone d. Energy Gap 32. Which of the following describes a semiconductor’s behavior at absolute zero temperature? a. It conducts electricity perfectly c. It has no energy bands b. It acts an insulator d. behaves like a metal 33. Polymers can be classified based on its physical properties. What type of polymer is described as rigid and has usually has high degree of crosslinking. It also doesn’t flow or soften when heated and usually degrade with bond when the polymers are getting broken? a. Elastomers c. Thermosets b. Thermoplastics d. Graft co-polymer 34. The following examples are considered as Natural Polymers EXCEPT: a. Chitin c. Polystyrene b. Keratin d. Cellulose 35. Composites are typically classified based in the type od dispersive phase used. Among the choices, which is not considered to be a type of composites? a. Fiber reinforced c. Structural b. Particle reinforced d. Ceramic dispersive