Chemistry Bank PDF

**SECTION I** 30 M **Encircle The Best Choice from a,b,c and of The Following** 1\. The mineral acids is more corrosive than 2\. Iron metal, is corroded easily in atmosphere due to a- higher activity of iron. b- the nature of Iron ores. c- easily react with oxygen. d- both a and b. 3\. The p...

**SECTION I** 30 M **Encircle The Best Choice from a,b,c and of The Following** 1\. The mineral acids is more corrosive than 2\. Iron metal, is corroded easily in atmosphere due to a- higher activity of iron. b- the nature of Iron ores. c- easily react with oxygen. d- both a and b. 3\. The passivity to corrosion, depends on the 4\. Pitting corrosion takes place due to 5\. Cathoic reaction in neutral medium of Galvanic corrosion is a- reduction reaction. b- H~2~ O + 0.5 O~2~ + 2e 2 OH^-^. c- M M^+n^ + ne. d- oxidation reaction. 6\. Decreasing velocity of water through pipeline, will be 7\. Mainly factors affecting Atmospheric corrosion are 8\. The anodic reaction of Mg -- Fe galvanic cell is c- Fe → Fe^+2^ + 2e. 9\. Rusting of Iron increasing with a- increasing humidity and porosity of metal oxide layer. b- increasing the humidity. c- increasing the potential. 10\. 5. As shown in Fig. corrosion can be takes place owing to 11\. Intercrystalline peneteration of alloy tends to 12\. Corrosion of Zinc metal when immersed in strong acidic medium, its considered as 13\. Nickel metal (as barrier ) is used to protect **atmospheric** corrosion , its barrier act as d- passive barrier. 14. The Sacrificial anode of Cathodic protection technique must be 15\. The mainly condition of Impressed current method of Cathodic Protection is a- Corrosion potential must be greater than power supply potential. b- reveries anodic reaction. c- potential Protection is greater than Corrosion potential. d- both a and b. 16\. Sacrificial anode method of Cathodic Protection, can be used in 17\. To protect Iron article from **atmospheric** corrosion by electroplating method with Copper metal. Copper must be act as a. inert barrier. b. anode in electroplating cell. c. perfect barrier. d. both b and c. 18\. Corrosion of corrosive electrolyte medium inside pipeline. To decrease or Prevent the following technique is use 19\. Formation of CO during combustion of Fuel is owing to b- Increasing or decreasing the viscosity. c- change the Flash point. d- both a and b. 20\. The following parameters of the Fuel are tends to a good combustion d- Higher specific gravity and Hydrogen content. 21\. Ash content of a fuel composed of a- organic impurities in the fuel. b- burn compounds. c- non burn compounds. d- Carbon residue. 22\. Increase % of sulphur in the fuel, tends to a- formation of corrosive medium. b- corrosion. c- low the efficiency. d- all of the above. 23\. Fuel is defined as a- compound composed of Carbon and Hydrogen. b- composed of C and H, and easily burn in air. c- compound given a large amount of heat. d- both b and c. 24\. Surface tension of fuel is must be a- low. b- high. c- medium. d- lower cohesive and adhesive forces. 25\. To removal Dissolved oxygen in feeding water of boiler (at High Pressure) can be used a- reducing agent. 26\. Cation exchange resin can be used to 27\. To removal of Oil and Suspended Colloids form water can be use a- reducing agent. d- Alum. 28\. Saturated cation exchange resin can be regenerated by using 29\. Dissolved alkaline gases in water can be removed by a- chemical reaction. b- precipitation the gas. c- acidic solution. a. Ca and Mg salts. b. Can and Mg bicarbonate salts. c. Ca and Mg nitrate salts. d. none of the above. 33\. Metallic structure made from copper,when exposed to ammonia, its corroded due to 37\. Corrosion of Zinc metal when imersed in caustic soda solution, its considered as 39\. Galvanic corrosion takes place in case of the following c- different electrolytes. d- both a and c. 42\. Corrosion of Metal -- Metal oxide cell, its due to 43\. Bridge made from steel exposed to sea water, it's corroded owing to 44\. Non metalic structure is immersed in salt water, the structure willbe 45\. Stress corrosion cracking of different alloys takes place due to a- temperature. b- specific corrosive environent. c- apllyed stress. d- both b and c a. Specific corrosive environment. b. Sodium hydroxide solution. c. Chloride solution. d. Alkaline solution. a. The cohesive force between the grains. b. PPT of impurities at grain boundaries. c. The structure and the grain boundaries. d. Loss the coherence between the grains. 51\. Coating protection mainly means that formation of a- protective barrier. b- adhesive layer. c- none porous barrier. d- none of above. 52\. Mechanism of Thio-phenol as inhibitors is 53\. Cathodic inhibitors (as protection technique) are used to 55\. The organic acids is less corrosive than 58\. Pitting corrosion takes place due to 59\. Cathodic reaction in strong acid medium of Galvanic corrosion is a- reduction reaction. b- H~2~ O + 0.5 O~2~ 2 OH^-^. c- M M^+n^ + ne. d- none of the above. 60\. Decreasing velocity of water through pipeline, will be 62\. The anodic reaction of Fe - Cu galvanic cell is c- Fe → Fe^+2^ + 2e. 64\. Corrosion of Metal -- Metal oxide cell, its due to 62\. Corrosion of Metal when dissolved in strong acidic medium, its considered as 64. The Sacrificial anode of Cathodic protection technique must be 66\. Sacrificial anode method of Cathodic Protection, can be used in 67\. To protect Iron article from atmospheric corrosion by electroplating method with Silver metal. Silver must be act as a. inert barrier. b. cathode in electroplating cell. c. perfect barrier. d. both a and b. 71\. Non burn compounds during the combustion of fuel is considered as a- organic impurities in the fuel. b- inorganic compounds. c- Ash. e. Carbon residue. a. Ca and Mg chloride salts. b. Can and Mg bicarbonate salts. c. Ca and Mg sulphate salts. d. none of the above. 92\. The cathodic reaction of Differential aeration corrosion is c- H2O + 1/2 O2 + 2e → 2OH^-^. 97. Successful coating protection depends mainly on =================================================== a- good suitable barrier. ========================= b- formation of inert barrier. ============================== c- good cleaning of the surface. ================================ d- all of the above. ==================== 98. Intergranular corrosion takes place due to ============================================== a- potential difference. ======================== b- loss the coherence forced between the grains. ================================================ c- precipitation of impurities at grain boundaries. =================================================== d- both b and c. ================ 99\. Inert barrier protect the corrosion in the following medium d- all of above. 100\. Sacrificial anode method of Cathodic Protection, can be used in 101\. The mainly condition of Impressed current method of Cathodic Protection is 102\. The mainly condition of Impressed current of cathodic protection is a- reverse anodic reaction. b- protection potential is greater than corrosion potential. c- high potential power supply. d- none of above. 103\. To decrease the corrosion of corrosive solution inside metallic pipeline, a. Cathodic protection. b. Inhibitors. c. Coating protection. d. Galvanization method. 104\. incomplete combustion of Fuel is owing to a- lower viscosity. b- Higher viscosity. c- insufficient amount of air. d- all of above. 105\. Ash content of Fuel is composed of a- Carbon residue. b- non-burn compounds. c- impurities. d- both a and b. 108\. The following parameters of the Fuel tends to good ignition. a- lower Flash point. b- more % of Hydrogen content. c- higher specific gravity and viscosity. d- both a and b. 109\. Permanent Hardness of water, it's due to presence of the following salts 110\. Sedimentation process in water treatment is used to removal 111\. Removal of Dissolved oxygen of feeding water of boilers (low pressure) can be used a- reducing agent. b- sodium sulphite salt. c- hydrazine. d- sodium sulphate salt. 112\. To avoid formation of Oils and Colloids in water can be used a- Sodium tri-phosphate. b- Alum as coagulating agent. c- Reducing agent. d- both b and c. 113\. pH of feeding water of Boilers must be equals a- pH = 7. b- pH less than 7. c- pH more than 7. d- pH 8 -- 10. 114. The cell which convert the electrical energy to chemical energy is a. Solar cell. b. Galvanic cell. c. Electrolytic cell or Electrolysis cell. d. none of the above. 115. The mineral acids is more corrosive than 116. Electrode potential refers to the a. Cell potential. b. Metal potential. c. Potential of the power supply. d. none of the above. 120\. The cathodic reaction of Mg -- Fe galvanic cell in neutral medium is c- Fe → Fe^+2^ + 2e. 123\. Different metals such as copper and aluminum are connected to each other and immersed in non-electrolyte solution. The metal will be corroded is\ a- both of aluminum and copper. 124\. The passivity to corrosion, depends on the 125\. Decreasing velocity of water through pipeline, will be 126\. Chromium metal (as barrier) is used to protect atmospheric corrosion, its barrier act as d- passive barrier. 127\. To protect steel ship hull from the corrosion, which the following protection methods can be used: a. Coating by paints. b. Sacrificial anode method. c. Impressed current method. d. all of the above. 128\. The mainly condition of sacrificial anode method of Cathodic Protection is a- Corrosion potential must be greater than power supply potential. b- protected metallic structure must be cathode. c- potential Protection is greater than Corrosion potential. d- both a and b. 131\. Metal exposed to acidic vapor, the metal will be corroded owing to a- chemical corrosion. b- uniform corrosion. c- non-uniform corrosion. d- none of above. 132\. Higher calorific value of fuel is not actual value owing to 133\. Ash content of a fuel composed of a- organic impurities in the fuel. b- inorganic compounds. c- burnt compounds. d- Carbon residue. 135\. incomplete combustion of Fuel is tends to b- Increasing or decreasing the viscosity. c- change the Flash point. d- Formation of CO during 137\. Higher or lower viscosity of fuel tends to a- complete combustion. b- incomplete combustion. c- good ignition. d- both a and c. 138\. Suspended solids and colloid impurities are removed from water by 139\. Permanent Hardness of water, its due to presence of the following 140\. The water treated form Cation and Anion exchange resins is considered to be: 141 Water temporary hardness occurs as a result of: 143\. Defects of Scale formation inside the hot tubes will be causes a- decrease the heat transfer. 146\. The mechanism of anodic inhibitors depends mainly upon a- decrease the corrosion current. ================================== b- increase of anodic polarization. ==================================== c- electron -- electron interaction. ===================================== d- forming adsorbed passive layer. 147\. The conditions of electroplating method of coating protection are a- D.C power supply and non- electrolyte solution. ================================================== b- the electrolyte solution is related to coating metal. ======================================================== c- coating metal act as anode. ============================== d- both b and c. ================ 148\. To decrease the corrosion inside pipe line of crude petroleum oil (contains corrosive medium), the suitable method is a- Cathodic protection. b. Coating protection. c. Inhibitors. d. all of the above. 149. The mechanism of impressed current method of cathodic protection is a. decrease the corrosion current. b. reveries the anodic reaction. c. potential of power supply is greater than potential of corrosion. d. both a and c. 150\. The following barrier is resist different corrosive environment a. sacrificial barrier. b. inert barrier. c. nickel barrier. d. perfect barrier. 152\. Sacrificial anode method of cathodic protection, can be used in a- neutral medium. ================== b- inactive medium. =================== c- different medium. ==================== d- both a and b. 153\. Inhibitors means that a chemical compounds used to a- increase the anodic and cathodic polarization. ================================================= b- increase the cell resistance. ================================ c- decrease the corrosion. ========================== d- all of the above. ==================== 154\. As shown in Fig. using A.C current, its a. suitable protection. b. good protection. c. incorrect protection. d. impressed current protection. 156. To protect pipe line of crude petroleum oil (contains corrosive medium) can ================================================================================ be use the best method ====================== a. Cathodic protection. ==================== b. Paints. ======= c. both a and b. ============= d. none of above. ============== 157. Mechanism of Inhibitors as protection technique tends to ============================================================= a- formation of adhesive layer. =============================== b- electron --electron inter action. ==================================== c- elimination active corrosive agent. ====================================== d- decrease the corrosion. ========================== 158. The mainly conditions of Impressed current of Cathodic protection is ========================================================================= a- more anodic. =============== b- protection potential ≥ corrosion potential. ============================================== c- insoluble. ============= d- both a and b. ================ 159. As shown in Fig. its ========================= a- correct protection. ====================== b- incorrect protection. ======================== c- efficient protection. ======================== d- both a and c. ================ 160. Presence of the following causes corrosion inside the boilers ================================================================== a- chloride salts and acidity. ============================== b- dissolved oxygen and bacteria. ================================= c- bacteria sulfate. ==================== d- all of above. ================ 161. the Scale which is form when using un-treatment water considered that ========================================================================== a- dissolved salts in cold water forming dry adhesive layer. ============================================================ b- oils and colloids impurities. ================================ c- suspended impurities. ======================== d- both a and b. ================ 162. Permanent Hardness of water is due presence of the following ================================================================= a- cations o f Ca and Mg. ========================= b- Ca and Mg salts. =================== c- Ca and Mg sulphate salts. ============================ d- sulphate salts. ================== 163. Formation of Scale inside the boilers tends to =================================================== a- decrease the heat transfers and more consumption of fuel. ============================================================ b- wet steam and none adhesive layer. ===================================== c- stress heat on the surface. ============================== d- both a and c. ================ 165. Decreasing Specific gravity of a fuel is tends to ====================================================== a- increasing percentage of Paraffin's in the fuel. =================================================== b- increasing calorific value of the fuel. ========================================== c- good ignition. ================= d- both a and c. ================ 166. The following parameters are tends to good combustion of fuel ================================================================== a- high % of hydrogen content. ============================== b- lower specific gravity and surface tension. ============================================== c- both a and b. ================ d- higher specific gravity and hydrogen content. ================================================ 167. pH of water which is enter the Anion exchange resin equals =============================================================== a- 7. ===== b- less than 7. =============== c- more than 7. =============== d- 10. ====== 169. The feeding water of boilers must have the following conditions ==================================================================== a- Deionized water. =================== b- free from dissolved oxygen. ============================== c- less conductor. ================== d- both a and b. ================ 170. Flash point of a fuel is indicating to =========================================== a- The density of the fuel. =========================== b- Degree of evaporation. ========================= c- Start energy to burn the fuel. ================================= d- all of the above. ==================== 171. Lowering Calorific value of Fuel is due to =============================================== a- the component of Fuel. ========================= b- water formation. =================== c- Presence of H~2~. ===================== d- all of the above. ==================== 175. The sludge which can be formed inside water pipes is considered as ======================================================================= a- impurities in water. ======================= b- presence of colloids, insoluble and turbidity in water. ========================================================== c- presence of dissolved salts. =============================== d- all of above. ================ 176. Deionized water is free from the following =============================================== a- dissolved salts. =================== b- ionized impurities. ====================== c- dissolved gases. =================== d- both a and b. ================ 177. The amount of Energy realized from 1 Kg. fuel is consider ============================================================== a- calorific value. =================== b- net calorific value. ======================= c- heat evolved. ================ d- both b and c. ================ 1778. Increase in Hydrogen content of fuel, tends to ==================================================== a- change the viscosity and specific gravity. ============================================= b- good ignition. ================= c- increase the calorific value. ================================ d- all of the above. ==================== 178. Increasing % Ash in the fuel tends to ========================================== a- Erosion corrosion and blocking. ================================== b- increasing specific gravity of fuel. ======================================= c- Erosion and blocking. ======================== d- both b and c. ================ 179. Good ignition fuel has Flash point ======================================= a- higher flash point. ====================== b- lower flash point. ===================== c- lower than specific gravity of fuel. ======================================= d- none of the above. ===================== 180. Saturated anion exchange resin can be generated or activated by washing with ================================================================================= a- alkaline solution. ===================== b- sodium hydroxide solution. ============================= c- diluted sodium hydroxide solution. ===================================== d- all of the above. ==================== 181. Distilled water is considered as ===================================== a- Pure water. ============== b- Water free from impurities. ============================== c- Water free from ionized and none ionized salts. ================================================== d- Water free from ionized salts. ================================= 182. Increasing % of paraffins in the fuel is associated with ============================================================= a- decreasing specific gravity of the fuel ========================================== b- a good ignition. =================== c- higher calorific value. ========================== d- both a and b. ================ 183. Ash content of a fuel refers to ==================================== a- impurities in the fuel. ========================== b- sulfur compounds. ==================== c- non burn compounds. ======================= d- both a and c. ================ 184. Formation of Carbon monoxide in combustion of fuel is due to ================================================================= a- lower or higher viscosity. ============================= b- lowering the efficiency. =========================== c- less amount of air. ====================== d- both a and c. ================ 185. Kinematic viscosity is related to ====================================== a- nature of surface (rough or smooth). ======================================= b- the adhesive force. ====================== c- the motion. ============== d- all of above. ================ 186. Decrease of hydrogen content of a fuel is associated with ============================================================== a- decreasing calorific value. ============================== b- increasing specific gravity and viscosity. ============================================= c- both a and b. ================ d- increasing % of ash. ======================= 187. Increase in hydrogen content of a fuel tends to ==================================================== a- good ignition. ================= b- decreasing viscosity and specific gravity. ============================================= c- increasing calorific value. ============================== d- all of above. ================ 189. The Dynamic viscosity of a fuel is related to the ====================================================== a- cohesive force. ================== b- adhesive force. ================== c- motive force. ================ d- both a and c =============== 190. Good ignition of the fuel is owing to ========================================== a- complete combustion. ======================= b- high % of hydrogen in the fuel. ================================== c- increase % of paraffins in the fuel. ======================================= d- all of the above. ==================== 191. Incomplete combustion of fuel is owing to ============================================== a- lower or higher viscosity. ============================= b- insufficient amount of air. c- both a and b. 192\. Good combustion fuel has specific gravity a- lower value. b- higher value. c- lower than flash point. d- higher flash point. **Section II** 10 M **True or False** 1. Calorific value of Fuel is defined as the amount of energy evolved when complete burn one unit mas of fuel in air. ( T ) 2. Dynamic viscosity is relating to the motion. ( F ) 3. Ion exchange resin used to removal non ionized salts dissolved in water. (F ) 4. Scale salts characterized by bad conductor heat. ( T ) 5. Inert barrier, resist the corrosion in different environments. ( F ) 6. Inhibitors that chemical compounds is used to decrease the corrosion. ( T ) 7. Pitting and Intergranular corrosion are localized electrochemical reactions. ( T ) 8. Uniform corrosion is localized form. ( F ) 9. Non-metallic structure when exposed to sea water, Differential aeration corrosion takes place. ( F ) 10. 11\. Ion exchange resin used to removal all salts in water. ( F ) takes place. ( F ) 21\. Inhibitors is used in gas and liquid medium to decrease the corrosion ( T ) Potential difference. ( F ) Fuel is defined as the amount of energy evolved when complete burn one unit mas of fuel in air. ( F ) corrosion. ( T ) 61\. Ion exchange resin used to removal non ionized salts dissolved in water. ( F ). bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb