LABORATORY MANUAL FOR ENGINEERING CHEMISTRY EXPERIMENTS Prepared by Dr. JYOTI MITTAL (Assistant Professor) Department of Chemistry, MANIT Instructions for Laboratory Record writing: BLANK SIDE Neat Labelled Diagram (in pencil) Observation in tabular form (in pen) Calculations (in pen) /Graph (in pencil & pasted) RULED SIDE Experiment Number and Date on which experiment was performed Aim/Objective of the experiment Theory/Principle on which experiment is based Description of the Apparatus Procedure followed while carrying out the experiment Inference / Result Sources of Error and Precautions taken to Eliminate or to Minimize them **Students should submit the record of the previous experiments when they come for practical-work next time. Experiment No. Aim: To determine the Flash Point and Fire Point of the lubricating oil by Abel’s Apparatus. Materials Required: Abel’s apparatus, Lubricating oil, Thermometer, Heater, Spirit lamp, Wooden sticks, Water Theory: Good lubricating oil should not volatize under the working temperature and even if vaporization takes place, the vapors should not form inflammable mixture with air under the condition of lubrication. The flash and fire points are helpful in providing safety limit against fire hazard during their storage and their industrial use. Flash point of the oil should be higher than the operating temperature of the machine. Flash Point: Flash point is the lowest temperature at which the lubricating oil gives off enough vapors to ignite for a moment when a test flame is brought near to it. Fire Point: Fire point is the lowest temperature at which the vapors of the lubricating oil burn continuously for at least five second when a test flame is brought near to it. Diagram of the Apparatus: Description of the Apparatus: To be written point-wise by student. Procedure: 1. Remove the water jacket from heater and fill it with hot water (keeping it in the basin) up to the top but afterwards empty out at least half a mug to create space for vapors. Put it back on the heater. 2. Fill the oil up to the pointer in the oil cup. 3. Fix the thermometer so that it should dip in oil and not strike the bottom of the oil cup. It should be firmly placed with the readings towards you. 4. Shutter on the lid of oil cup should remain close to prevent the escaping of oil vapors. It should be opened only when testing is to be done. 5. Least count of thermometer is 1 0C, so readings should be recorded at every one degree rise or fall of temperature. 6. Switch on the heater and start checking for flash with flame (on wooden splinter) after 40 0 C. 7. Flame should be kept at the mouth of shutter. It should not be too much high in air and never inside the oil cup. 8. Note your findings with increasing temperature as “No Observation” or “Flash is observed” or “Fire is observed”. 9. Check up to first fire only and switch off the heater. 10. Temperature will continue to rise even after switching off the heater but testing should not be performed. 11. TESTING ABOVE FIRST FIRE IS STRICTLY “NOT ALLOWED”. 12. Check for fire and flashes during decreasing temperatures also. Continue till you get “No Observation” 3 – 4 times. Sample observation table: 1. While increasing the temperature: S. No. Temperature (0C) 1 40 2 41 3 42 4 44 5 45 6 47 7 49 8 50 9 51 10 53 11 54 Observation No Observation No Observation No Observation No Observation No Observation Flash is observed Flash is observed No Observation Flash is observed No Observation Fire is observed 2. While decreasing the temperature: S. No. Temperature (0C) 1 54 2 53 3 52 4 51 5 50 6 49 7 48 8 47 9 46 10 45 11 44 12 43 Observation Fire is observed Fire is observed Flash is observed No Observation Flash is observed No Observation Flash is observed No Observation Flash is observed No Observation No Observation No Observation Result: Flash point of the lubricating oil is 46 0C. Fire point of the lubricating oil is 53 0C. Precautions: 1. 2. 3. 4. 5. 6. Do not fill the oil above the pointer in the oil cup. Fix the thermometer as instructed in the procedure. Water jacket should have water less than full to avoid spilling of water on heater. Keep the shutter close. Open it only while checking for flash or fire. DO NOT EVER CHECK ABOVE FIRST FIRE. Do not try to remove heated oil cup by yourself. Ask the lab assistant to do so. Experiment No. Aim: To determine the Flash Point and Fire Point of the lubricating oil by Pensky Marten’s Apparatus. Materials Required: Pensky Marten’s apparatus, Lubricating oil, Thermometer, Heater, Spirit lamp, Wooden sticks Theory: Good lubricating oil should not volatize under the working temperature and even if vaporization takes place, the vapors should not form inflammable mixture with air under the condition of lubrication. The flash and fire points are helpful in providing safety limit against fire hazard during their storage and their industrial use. Flash point of the oil should be higher than the operating temperature of the machine. Flash Point: Flash point is the lowest temperature at which the lubricating oil gives off enough vapors to ignite for a moment when a test flame is brought near to it. Fire Point: Fire point is the lowest temperature at which the vapors of the lubricating oil burns continuously for at least five second when a test flame is brought near to it. Diagram of the Apparatus: Description of the Apparatus: To be written point-wise by student. Procedure: 1. Fill the oil up to the grooved ring in the oil cup. 2. Fix the thermometer so that it should dip in oil and not strike the bottom of the oil cup. It should be firmly placed with the readings towards you. 3. Shutter on the lid of oil cup should remain close to prevent the escaping of oil vapors. It should be opened only when testing is to be done. 4. Least count of thermometer is 2 0C, so readings should be recorded at every two degrees rise or fall of temperature, which means ODD readings cannot be taken. 5. Switch on the heater and start checking of flash with flame (on wooden splinter) after 100 0 C. 6. Flame should be kept at the mouth of shutter, not too much high in air and never inside the oil cup. 7. Note your finding with increasing temperature as “No Observation” or “Flash is observed” or “Fire is observed”. 8. Check up to first fire only and switch off the heater. 9. Temperature will continue to rise even after switching off the heater but testing should not be performed. 10. TESTING ABOVE FIRST FIRE IS STRICTLY “NOT ALLOWED”. 11. Check for fire and flashes during decreasing temperatures also. Continue till you get “No Observation” 3 – 4 times. Sample Observation Table: 1. While increasing the temperature: S. No. Temperature (0C) 1 100 2 106 3 112 4 118 5 122 6 124 - 180 7 184 8 186 9 188 10 190 11 192 12 194 13 196 14 200 15 204 16 206 Observation No Observation No Observation No Observation No Observation No Observation No Observation No Observation Flash is observed Flash is observed No Observation Flash is observed No Observation No Observation Flash is observed No Observation Fire is observed 2. While decreasing the temperature: S. No. Temperature (0C) 1 206 2 204 3 202 4 200 5 198 6 196 7 194 8 192 9 190 10 188 11 186 12 184 13 182 14 180 15 178 Observation Fire is observed Fire is observed Flash is observed No Observation Flash is observed No Observation Flash is observed No Observation Flash is observed No Observation No Observation Flash is observed No Observation No Observation No Observation Result: Flash point of the lubricating oil is 184 0C. Fire point of the lubricating oil is 204 0C. Precautions: 1. 2. 3. 4. 5. Do not fill the oil above the grooved ring in the oil cup. Fix the thermometer as instructed in the procedure. Keep the shutter close. Open only while checking for flash or fire. DO NOT EVER CHECK ABOVE FIRST FIRE. Do not try to remove heated oil cup by yourself. Ask the lab assistant to do so. Experiment No. Aim: To determine the Flash Point and Fire Point of the lubricating oil by Cleveland’s Apparatus. Materials Required: Cleveland’s apparatus, Lubricating oil, Thermometer, Heater, Spirit lamp, Match sticks, Wooden board Theory: Good lubricating oil should not volatize under the working temperature and even if somevaporization takes place, the vapors should not form inflammable mixture with air under the condition of lubrication. The flash and fire points are helpful in providing safety limit against fire hazard during their storage and their industrial use. Flash point of the oil should be higher than the operating temperature of the machine. Flash Point: Flash point is the lowest temperature at which the lubricating oil gives off enough vapors to ignite for a moment when a test flame is brought near to it. Fire Point: Fire point is the lowest temperature at which the vapors of the lubricating oil burns continuously for at least five second when a test flame is brought near to it. Diagram of the Apparatus: Description of the Apparatus: To be written point-wise by student. Procedure: 1. Fill the oil slightly LESS than the grooved ring in the oil cup. 2. Fix the thermometer so that it should dip in oil and not strike the bottom of the oil cup. It should be firmly placed with the readings towards you. 3. Least count of thermometer is 2 0C, so readings should be recorded at every two degrees rise or fall of temperature, which means ODD readings cannot be taken. 4. Due to open cup chances of oil catching fire is more, thus extra precautions and attention should be taken. 5. Switch on the heater and start checking of flash with flame (on wooden splinter) after 100 0 C. 6. Flame should be kept at the level of the cup, not too much high in air and never bend stick downwards inside the oil cup. 7. Note your finding with increasing temperature as “No Observation” or “Flash” or “Fire”. 8. Check up to first flash only and switch off the heater so as to prevent overheating of the oil. 9. Temperature will continue to rise even after switching off the heater. Keep on testing to get the first FIRE. 10. TESTING ABOVE FIRST FIRE IS STRICTLY NOT ALLOWED. 11. Check for fire and flashes during decreasing temperatures also, till you get “No Observation” 3 – 4 times. Sample Observation Table: 1. While increasing the temperature: S. No. Temperature (0C) 1 100 2 106 3 112 4 118 5 122 6 124 - 180 7 184 8 186 9 188 10 190 11 192 12 194 13 196 14 200 15 204 16 206 Observation No Observation No Observation No Observation No Observation No Observation No Observation No Observation Flash is observed Flash is observed No Observation Flash is observed No Observation No Observation Flash is observed No Observation Fire is observed 2. While decreasing the temperature: S. No. Temperature (0C) 1 206 2 204 3 202 4 200 5 198 6 196 7 194 8 192 9 190 10 188 11 186 12 184 13 182 14 180 15 178 Observation Fire is observed Fire is observed Flash is observed No Observation Flash is observed No Observation Flash is observed No Observation Flash is observed No Observation No Observation Flash is observed No Observation No Observation No Observation Result: Flash point of the lubricating oil is 184 0C. Fire point of the lubricating oil is 204 0C. Precautions: 1. Due to open cup chances of oil catching fire is more, thus extra precautions and attention should be taken. 2. Fill the oil slightly below the grooved ring in the oil cup. 3. Fix the thermometer as instructed in the procedure. 4. Switch off the heater at the first FLASH so as to prevent overheating of the oil. 5. DO NOT EVER CHECK ABOVE FIRST FIRE. 6. Do not try to remove heated oil cup by yourself. Ask the lab assistant to do so. 7. IN CASE OF OIL CATCHING FIRE COVER THE OIL CUP WITH WOODEN BOARD TO STOP THE FIRE. DO NOT BLOW IN THE FIRE. AND ALSO, DO NOT TRY TO REMOVE THE OIL CUP FROM HEATER. Experiment No. Aim: To determine the Viscosity-Index of the lubricating oil by Redwood Viscometer 1. Materials Required: Redwood Viscometer, Lubricating oil, Thermometer, Stop-watch, Water Theory: Viscosity of liquids decreases with increasing temperature and, consequently, the lubricating oil becomes thinner as the operating temperature increases. Hence, viscosity of good lubricating oil should not change much with change in temperature, so that it can be used continuously, under varying conditions of temperature. The rate at which the viscosity of lubricating oil changes with temperature is measured by an arbitrary scale, known as Viscosity Index (V. I). If the viscosity of lubricating oil falls rapidly as the temperature is raised, it has a low viscosity index. On the other hand, if the viscosity of lubricating oil is only slightly affected on raising the temperature, its viscosity index is high. Diagram of the Apparatus: Description of the Apparatus: To be written point-wise by student Diameter of the orifice: 1.62mm Length of the capillary: 10mm Procedure: 1. Close the orifice of the oil-cup properly with the valve and fill the oil up to the pointer. 2. Place the measuring beaker beneath the orifice to collect the oil as it drains out. 3. Fix the thermometer so that it should dip in oil and not strike the bottom of the oil cup. It should be firmly placed with the readings towards you. 4. Note the temperature of oil. 5. Remove the valve to start collecting the oil and also start the stop-watch immediately. 6. Collect 50 ml of the oil and note down the time taken. 7. Fill back the same oil in the oil-cup. Pour lukewarm water in the water bath approximately up to the level of oil. 8. Rotate the stirrer and wait for the temperature of the oil to stabilize. It should be roughly 4-6 0C above the first reading. 9. Again note the temperature of oil, remove the valve to start collecting the oil and also start the stop-watch immediately, collect 50 ml of the oil and note down the time taken. 10. Fill back the same oil in the oil-cup. Flow out small amount of water and fill more hot water so as the raise the temperature to 4-6 0C above the second reading. 11. Repeat to get at least five readings to plot V.I. curve. Sample Observation Table: S. No. 1. 2. 3. 4. 5. Temperature of oil (in 0C) 23 (Room Temperature) 29 35 42 47 Time of collection of 50 ml of oil (in sec) 185 176 156 123 108 Calculations: Plot the graph between Temperature on X-axis and Time on Y-axis (on graph paper). Join the points to get hyperbolic curve. Do not join the points by scale. Leave the points not falling on curve. Result: Graph shows decrease in time of collection of oil with increase in temperature, which indicates fall in viscosity of lubricating oil with rising temperature. Precautions: 1. Fill the oil up to pointer only. Do not fill only 50 ml. 2. Place the measuring beaker exactly beneath the orifice to collect the oil without any spillage. 3. Fix the thermometer properly. 4. Small debris can clog the small orifice and change its flow rate. Keep close watch on the rate of flow of oil. 5. In case of clogging, report the matter to lab assistant to clear the orifice. 6. Raise the temperature in step-wise manner. 7. Stabilize the temperature of the oil before taking the reading. 8. While adding water, make sure it should not fall in oil-cup to prevent the formation of emulsion. Experiment No. Aim: To determine the Viscosity-Index of the lubricating oil by Redwood Viscometer 2. Materials Required: Redwood Viscometer, Lubricating oil, Thermometer, Stop-watch, Water Theory: Viscosity of liquids decreases with increasing temperature and, consequently, the lubricating oil becomes thinner as the operating temperature increases. Hence, viscosity of good lubricating oil should not change much with change in temperature, so that it can be used continuously, under varying conditions of temperature. The rate at which the viscosity of lubricating oil changes with temperature is measured by an arbitrary scale, known as Viscosity Index (V. I). If the viscosity of lubricating oil falls rapidly as the temperature is raised, it has a low viscosity index. On the other hand, if the viscosity of lubricating oil is only slightly affected on raising the temperature, its viscosity index is high. Diagram of the Apparatus: Description of the Apparatus: To be written point-wise by student. Diameter of the orifice: 3.8 mm Length of the capillary: 15 mm Procedure: 1. Close the orifice of the oil-cup properly with the valve and fill the oil up to the pointer. 2. Place the measuring beaker beneath the orifice to collect the oil as it drains out. 3. Fix the thermometer so that it should dip in oil and not strike the bottom of the oil cup. It should be firmly placed with the readings towards you. 4. Note the temperature of oil. 5. Remove the valve to start collecting the oil and also start the stop-watch immediately. 6. Collect 50 ml of the oil and note down the time taken. 7. Fill back the same oil in the oil-cup. Pour lukewarm water in the water bath approximately up to the level of oil. 8. Rotate the stirrer and wait for the temperature of the oil to stabilize. It should be roughly 4-6 0C above the first reading. 9. Again note the temperature of oil, remove the valve to start collecting the oil and also start the stop-watch immediately, collect 50 ml of the oil and note down the time taken. 10. Fill back the same oil in the oil-cup. Flow out small amount of water and fill more hot water so as the raise the temperature to 4-6 0C above the second reading. 11. Repeat to get at least five readings to plot V.I. curve. Sample Observation Table: S. No. 1. 2. 3. 4. 5. Temperature of oil (in 0C) 25 (Room Temperature) 31 37 42 47 Time of collection of 50 ml of oil (in sec) 98 72 44 28 12 Calculations: Plot the graph between Temperature on X-axis and Time on Y-axis (on graph paper). Join the points to get hyperbolic curve. Do not join the points by scale. Leave the points not falling on curve. Result: Graph shows decrease in time of collection of oil with increase in temperature, which indicates fall in viscosity of lubricating oil with rising temperature. Precautions: 1. Fill the oil up to pointer only. Do not fill only 50 ml. 2. Place the measuring beaker exactly beneath the orifice to collect the oil without any spillage. 3. Fix the thermometer properly. 4. Small debris can clog the small orifice and change its flow rate. Keep close watch on the rate of flow of oil. 5. In case of clogging, report the matter to lab assistant to clear the orifice. 6. Raise the temperature in step-wise manner. 7. Stabilize the temperature of the oil before taking the reading. 8. While adding water, make sure it should not fall in oil-cup to prevent the formation of emulsion.
