Beaker & Flask Accuracy Lab
Transcription
Beaker & Flask Accuracy Lab
Beaker & Flask Accuracy Lab NAME:______________________________DATE:_____________PERIOD:_______ Question: Are the volume lines on beakers and Erlenmeyer flasks reliable enough to measure out liquids in a laboratory experiment? Hypothesis: Sketch and label a beaker, an Erlenmeyer flask and graduated cylinder below. Procedure: 1) Obtain the following four beaker sizes: 50-mL, 100-mL, 150-mL, 250-mL 2) Obtain the following four flask sizes: 50-mL, 125-mL, 250-mL, 500-mL 3) Fill each one to the first listed volume line with water. For example, the first volume line from the bottom on the 50-mL beaker is 10-mL. 4) Record the value for the first volume line of each beaker or flask in the appropriate column. For the 50-mL beaker that value would be 10-mL. 5) Transfer the water from the flask or beaker into the 100-mL graduated cylinder and record this value in the graduated cylinder column. Data and Calculations: Beaker First Volume Volume in or Line Graduated Flask Cylinder (OBSERVED) (ACTUAL) 50-mL Beaker 100-mL Beaker 150-mL Beaker 250-mL Beaker 50-mL Flask 125-mL Flask 250-mL Flask 500-mL Flask © DY Teacher Friendly Chemistry Absolute Error Percent Error Percent Accuracy Useful Equations: Absolute error = ⎪Actual − Observed⎪ Record to one decimal place. Percent Error = ⎪Actual-Observed⎪ x 100 Actual Show work for Absolute Error for the 50-mL beaker. Record to one decimal place. Show work for Percent Error for the 125-mL flask. What piece of glassware (beaker, flask, graduated cylinder) should be used to accurately measure out liquids? ________________________ Conclusion: Station # 1 Identification of Glassware Write the name of the glassware in the appropriate blank below. 1) _________ 2) ____________ 3) __________ 4) __________ 5) __________ Station # 2 Reading the Volume Read the volume of the colored water in each piece of glassware and list below. GLASSWARE READING Beaker Erlenmeyer flask Volumetric flask Buret Graduated cylinder Give an appropriate laboratory use for each of the following: Graduated cylinder © DY Teacher Friendly Chemistry Beaker Teacher Notes: Beaker and Flask Accuracy Lab At each lab station: 4 50-mL beakers 4 100-mL beakers 4 150-mL beakers 4 250-mL beakers 4 50-mL E. flasks 4 125-mL E. flasks 4 250-mL E. flasks 4 500-mL E. flasks 2 100-mL graduated cylinders At a central location: Station 1: Obtain the following pieces of glassware and place the appropriate numbered label on each. # 1 E. Flask # 2 Beaker # 3 Buret # 4 Volumetric Flask # 5 Pipet Station 2: Place colored water into each of the following pieces of glassware. 150-mL Beaker Fill with colored water to the 80mL line. 250-mL E. Flask Fill with colored water to the 150mL line. 100-mL Volumetric Flask Fill with colored water to the etched line. 50-mL Buret Fill with colored water to the 25.0mL line. 25-mL Grad. Cylinder Fill to the 20mL line. Teaching Tips: This activity is used at the very beginning of school to help students learn the different types of glassware and how to read the volume. The only safety concern for this lab is the amount of glassware that will be out and the breakage that could occur. Before the lab: Discuss with students how to read the meniscus by either using a practice worksheet, a drawing on the chalkboard, a demonstration or a PowerPoint presentation. A PowerPoint made by taking close-up pictures of glassware containing colored water is a great way to introduce and review. However a chalkboard drawing, explanation and a few example pieces of glassware at the teacher’s lab desk would be sufficient. If this method is used, tell the students to come up and check the samples after being dismissed to the lab. Have 3-5 pieces of glassware as sample readings. Use colored water and have a paper showing the correct volume to be read. This will help the students build confidence in their reading. © DY Teacher Friendly Chemistry Beaker & Flask Accuracy Lab NAME:______________________________DATE:_____________PERIOD:_______ Question: Are beakers and Erlenmeyer flasks accurate enough to measure out liquids in a laboratory experiment? Hypothesis: I believe the beakers and Erlenmeyer flasks are accurate enough because they both have volume measurement lines. Sketch and label a beaker, an Erlenmeyer flask and graduated cylinder below. Beaker E. Flask Graduated cylinder Procedure: 1) Obtain the four different beaker sizes listed below in the data table. 2) Obtain the four different flask sizes listed below in the data table. 3) Fill each one to the first listed volume line with water. 4) Record the value for the first volume line of each beaker or flask in the appropriate column. 5) Transfer the water from the flask or beaker into the 100-mL graduated cylinder and record this value in the graduated cylinder column. Data and Calculations: Beaker First Volume Volume in Absolute Percent Percent or Line Graduated Error Error Accuracy Flask Cylinder (OBSERVED) (ACTUAL) 50-mL 10mL 9mL 1mL 11.1% 88.9% Beaker 100-mL 20mL 22mL 2mL 9.1% 90.9% Beaker 150-mL 20mL 21mL 1mL 4.8% 95.2% Beaker 250-mL 50mL 49mL 1mL 2.0% 98.0% Beaker 50-mL 20mL 19mL 1mL 5.3% 94.7% Flask 125-mL 50mL 51mL 1mL 2.0% 98.0% Flask 250-mL 50mL 58mL 8mL 13.8% 86.2% Flask 500-mL 100mL 102mL 2mL 2.0% 98.0% Flask © DY Teacher Friendly Chemistry Useful Equations: Absolute error = ⎪Actual − Observed⎪ Record to one decimal place. Percent Error = ⎪Actual-Observed⎪ x 100 Record to one decimal place. Actual Show work for Absolute Error for the 50-mL beaker. Absolute error = / 9mL- 10mL / = 1-mL Show work for Percent Error for the 125-mL flask. Percent error = / 51mL – 50mL / x 100 = 1.96 Æ 2.0% 51mL What piece of glassware (beaker, flask, graduated cylinder) should be used to accurately measure out liquids? ___graduated cylinder_______ Conclusion: The readings from the four different beakers and flasks did not always match the reading on the graduated cylinder. Although the beakers and flasks have volume markings on them, they are not accurate enough to use in the lab to measure liquids. Station # 1 Identification of Glassware Write the name of the glassware in the appropriate blank below. 1) _E. flask____ 2) __Beaker____ 3) __Buret___ 4) __Vol Flask__ 5) _Pipet____ Station # 2 Reading the Volume Read the volume of the colored water in each piece of glassware and list below. GLASSWARE READING Beaker 80mL Erlenmeyer flask Volumetric flask 150mL 100mL Buret Graduated cylinder 25mL 20mL Give an appropriate laboratory use for each of the following: Graduated cylinder To measure the volume of liquids. © DY Teacher Friendly Chemistry Beaker To hold, transfer or mix liquids. Beaker & Flask Accuracy Lab Quiz NAME:______________________________DATE:_____________PERIOD:_______ True (A) or False (B) Place either an “A” or a “B” in the blank provided. 1) Flasks and beakers are more accurate than graduated cylinders. ________ 2) The following picture shows a graduated cylinder. ________ 3) The following picture shows a beaker. ________ Use the following data to answer questions 4-7. Data: Beaker & Flask Accuracy Size of Beaker or flask Graduated cylinder container measurement (mL) measurement (mL) 500-mL beaker 25 50 250-mL beaker 50 100 125-mL beaker 50 50 50-mL beaker 45 50 500-mL flask 29 50 250-mL flask 110 100 125-mL flask 45 50 50-mL flask 45 50 4) The 500-mL beaker had a percent error of… a. 5% b. 50% c. 25% d. 75% e. none of these 5) The 250-mL flask had a percent error of… a. 50% b. 100% c. 10% d. 25% e. none of these 6) Absolute error for the 125-mL flask was… a. 50-mL b. 0-mL c. 21-mL e. none of these d. 5-mL 7) The 50-mL beaker had an accuracy of… a. 80% b. 90% c. 10% d. 100% © DY Teacher Friendly Chemistry e. none of these Beaker & Flask Accuracy Lab Make-up NAME:______________________________DATE:_____________PERIOD:_______ Question: Are beakers and Erlenmeyer flasks accurate enough to measure out liquids in a laboratory experiment? Hypothesis: Sketch and label a beaker, an Erlenmeyer flask and graduated cylinder below. Procedure: 1) Obtain the four different beaker sizes listed below in the data table. 2) Obtain the four different flask sizes listed below in the data table. 3) Fill each one to the first listed volume line with water. 4) Record the value for the first volume line of each beaker or flask in the appropriate column. 5) Transfer the water from the flask or beaker into the 100-mL graduated cylinder and record this value in the graduated cylinder column. Data and Calculations: Beaker First Volume Volume in Absolute Percent Percent Line Graduated Error Error Accuracy or Flask Cylinder (OBSERVED) (ACTUAL) 50-mL 10mL 9mL Beaker 100-mL 20mL 22mL Beaker 150-mL 20mL 21mL Beaker 250-mL 50mL 49mL Beaker 50-mL 20mL 19mL Flask 125-mL 50mL 51mL Flask 250-mL 50mL 58mL Flask 500-mL 100mL 102mL Flask © DY Teacher Friendly Chemistry Useful Equations: Absolute error = ⎪Actual − Observed⎪ Record to one decimal place. Percent Error = ⎪Actual-Observed⎪ x 100 Record to one decimal place. Actual Show work for Absolute Error for the 50-mL beaker. Show work for Percent Error for the 125-mL flask. What piece of glassware (beaker, flask, graduated cylinder) should be used to accurately measure out liquids? __________________________ Conclusion: Station # 1 Identification of Glassware Write the name of the glassware in the appropriate blank below. 1) _E. flask____ 2) __Beaker____ 3) __Buret___ 4) __Vol Flask__ 5) _Pipet____ Station # 2 Reading the Volume Read the volume of the colored water in each piece of glassware and list below. GLASSWARE READING Beaker 80mL Erlenmeyer flask Volumetric flask Buret Graduated cylinder 150mL 100mL 25mL 20mL Give an appropriate laboratory use for each of the following: Graduated cylinder © DY Teacher Friendly Chemistry Beaker Nomenclature and Household Items NAME:______________________________DATE:_____________PERIOD:_______ Background: Many household items contain chemicals that are commonly used in everyday life. Some chemicals are edible while other compounds would be poisonous to consume. Many non-edible household chemicals are used as cleaners. Soaps, detergents, drain-openers, countertop sprays, oven sprays, furniture polish, air fresheners and floor cleaners are examples of chemical substances that are commonly used inside the home. Other chemicals are edible and can be used for cooking or in medication. Baking soda, sugar, salt and baking powder are all edible substances commonly used in cooking. Antacids, aspirin and vitamin C are edible substances that are used as medicines. Household items can be classified as acids (pH<7), bases (pH>7) or neutral (pH=7). Soaps, detergents, drain-openers, antacids and ammonia can be classified as bases. Antacids contain carbonates, bicarbonates and hydroxides to neutralize the hydrochloric acid in the stomach. Aspirin (acetyl salicylic acid), Vitamin C (ascorbic acid) and vinegar (solution of acetic acid) can be classified as acidic. Product containers list valuable information such as ingredients, warnings, customer service numbers and expiration dates. The chemical name listed first on the ingredient list is the main component of that substance. The warning label will vary with the chemical hazard of the main ingredient. In this lab many household items will be viewed to obtain the chemical name. The chemical name will then be used to write the formula of the compound. Procedure: 1) Visit each lab station and copy down the name of the substance. 2) Decide the main use for the substance (cooking, cleaning, medicine) and write in the usage column. 3) Look on the ingredient list to find the main component of the substance. Write the name of the main component in the appropriate column. 4) Looking at the name of the main component, write the formula of the substance. 5) Look to see if the substance has a warning or hazard listed. Write “Yes” if the substance has a hazard or warning. Write “No” if the substance does not list a hazard or warning. © DY Teacher Friendly Chemistry Data: Substance Substance Usage Name of main component in substance Formula of main component in substance Hazard or Warning 1 2 3 4 5 6 7 8 9 10 11 12 Conclusion: True or False 1) Warning labels occur mainly on substances that are used for cooking. ________ 2) NaCl and NaHCO3 are edible compounds used in cooking. __________________ 3) Sodium hypochlorite is used for soaking sore feet. ________________________ 4) Magnesium sulfate heptahydrate is used to bleach material. ________________ 5) The compound listed first on the ingredient list is the main component in that substance. ________________________________________________________ 6) The main component in shampoo is water. ______________________________ 7) Household substances can be classified as acidic, basic or neutral. ___________ 8) Ammonia, antacids and aspirin are acidic compounds. _____________________ 9) Antacids can contain OH-1, CO3-2, HCO3-1 ions. ___________________________ 10)Table salt and baking soda both contain a sodium ion. _____________________ © DY Teacher Friendly Chemistry Teacher Notes: Nomenclature and Household Items Set-up: Obtain 12 note cards and write numbers # 1-12. Evenly space cards around the lab tables. Tape the cards to the table. Take the twelve items and write numbers #1-12 on each with a permanent marker. Place the item by the appropriate card. Items: Items will vary by brand names. When looking for items to purchase, look on the back of the product label to make a match to the main ingredient. This activity can be stored from year to year in a box since the containers are never opened. The purpose of this activity is not only to transfer names to formulas but also to allow students to see household items in the lab and to make the association that everything is made up of chemicals. © DY Teacher Friendly Chemistry Nomenclature and Household Items NAME:______________________________DATE:_____________PERIOD:_______ Background: Many household items contain chemicals that are commonly used in everyday life. Some chemicals are edible while other compounds would be poisonous to consume. Many non-edible household chemicals are used as cleaners. Soaps, detergents, drain-openers, countertop sprays, oven sprays, furniture polish, air fresheners and floor cleaners are examples of chemical substances that are commonly used inside the home. Other chemicals are edible and can be used for cooking or in medication. Baking soda, sugar, salt and baking powder are all edible substances commonly used in cooking. Antacids, aspirin and vitamin C are edible substances that are used as medicines. Household items can be classified as acids (pH<7), bases (pH>7) or neutral (pH=7). Soaps, detergents, drain-openers, antacids and ammonia can be classified as bases. Antacids contain carbonates, bicarbonates and hydroxides to neutralize the hydrochloric acid in the stomach. Aspirin (acetyl salicylic acid), Vitamin C (ascorbic acid) and vinegar (solution of acetic acid) can be classified as acidic. Product containers list valuable information such as ingredients, warnings, customer service numbers and expiration dates. The chemical name listed first on the ingredient list is the main component of that substance. The warning label will vary with the chemical hazard of the main ingredient. In this lab many household items will be viewed to obtain the chemical name. The chemical name will then be used to write the formula of the compound. Procedure: 1) Visit each lab station and copy down the name of the substance. 2) Decide the main use for the substance (cooking, cleaning, medicine) and write in the usage column. 3) Look on the ingredient list to find the main component of the substance. Write the name of the main component in the appropriate column. 4) Looking at the name of the main component, write the formula of the substance. 5) Look to see if the substance has a warning or hazard listed. Write “Yes” if the substance has a hazard or warning. Write “No” if the substance does not list a hazard or warning. © DY Teacher Friendly Chemistry Data: Substance Substance Usage 1 Soaking salts Medicine 2 Cleaning 3 Drain opener Antacid Medicine 4 5 6 Vinegar Ammonia Salt Cooking Cleaning Cooking 7 8 Shampoo Baking Soda Cleaning Cooking 9 Hydrogen peroxide Concrete cleaner Bleach Medicine Root and algae killer Cleaning 10 11 12 Cleaning Cleaning Name of main component in substance Magnesium sulfate heptahydrate Sodium hydroxide Calcium carbonate Acetic Acid Ammonia Sodium chloride Aqua Sodium bicarbonate Hydrogen peroxide Hydrochloric acid Sodium hypochlorite Copper II sulfate pentahydrate Formula of main component in substance Hazard or Warning MgSO4• 7H2O YES NaOH YES CaCO3 YES HC2H3O2 NH3 NaCl NO YES NO H2O NaHCO3 NO NO H2O2 YES HCl YES NaOCl YES CuSO4•5H2O YES Conclusion: True or False 1) Warning labels occur mainly on substances that are used for cooking. __False__ 2) NaCl and NaHCO3 are edible compounds used in cooking. __________True____ 3) Sodium hypochlorite is used for soaking sore feet. ________________False____ 4) Magnesium sulfate heptahydrate is used to bleach material. _________False___ 5) The compound listed first on the ingredient list is the main component in that substance. ________________________________________________True____ 6) The main component in shampoo is water. ______________________True____ 7) Household substances can be classified as acidic, basic or neutral. ____True___ 8) Ammonia, antacids and aspirin are acidic compounds. _____________False____ 9) Antacids can contain OH-1, CO3-2, HCO3-1 ions. __________________True______ 10)Table salt and baking soda both contain a sodium ion. _____________True____ © DY Teacher Friendly Chemistry Nomenclature and Household Items Quiz NAME:______________________________DATE:_____________PERIOD:_______ Fill in the blank. 1) ______________________ is the main component in many drain openers. 2) _______________________ is known as table salt. 3) _______________________ is the active ingredient in vinegar. 4) Give the formula for calcium carbonate. ________________________________ 5) Give the formula for sodium bicarbonate. _______________________________ 6) Give the formula for copper II sulfate pentahydrate. ______________________ 7) Give the name for MgSO4• 7H2O. ______________________________________ 8) Give the name for NH3. _____________________________________________ 9) Give the name for NaOCl. ____________________________________________ True or False 10)____________Substances used for medicating and cleaning often contain a warning or hazard label. 11)____________Calcium carbonate and sodium bicarbonate are bases used in antacid tablets. 12)____________Bases have a pH greater than 7 while acids have a pH equal to 7. © DY Teacher Friendly Chemistry Nomenclature and Household Items Make-up NAME:______________________________DATE:_____________PERIOD:_______ Background: Many household items contain chemicals that are commonly used in everyday life. Some chemicals are edible while other compounds would be poisonous to consume. Many non-edible household chemicals are used as cleaners. Soaps, detergents, drain-openers, countertop sprays, oven sprays, furniture polish, air fresheners and floor cleaners are examples of chemical substances that are commonly used inside the home. Other chemicals are edible and can be used for cooking or in medication. Baking soda, sugar, salt and baking powder are all edible substances commonly used in cooking. Antacids, aspirin and vitamin C are edible substances that are used as medicines. Household items can be classified as acids (pH<7), bases (pH>7) or neutral (pH=7). Soaps, detergents, drain-openers, antacids and ammonia can be classified as bases. Antacids contain carbonates, bicarbonates and hydroxides to neutralize the hydrochloric acid in the stomach. Aspirin (acetyl salicylic acid), Vitamin C (ascorbic acid) and vinegar (solution of acetic acid) can be classified as acidic. Product containers list valuable information such as ingredients, warnings, customer service numbers and expiration dates. The chemical name listed first on the ingredient list is the main component of that substance. The warning label will vary with the chemical hazard of the main ingredient. In this lab many household items will be viewed to obtain the chemical name. The chemical name will then be used to write the formula of the compound. Procedure: 1) This is a make-up lab. Take your lab sheet to the grocery store. Find the substances in the data table and use the label on those substances to fill out the chart. 2) Decide the main use for the substance (cooking, cleaning, medicine) and write in the usage column. 3) Look on the ingredient list to find the main component of the substance. Write the name of the main component in the appropriate column. 4) Looking at the name of the main component, write the formula of the substance. 5) Look to see if the substance has a warning or hazard listed. Write “Yes” if the substance has a hazard or warning. Write “No” if the substance does not list a hazard or warning. © DY Teacher Friendly Chemistry Data: Substance Substance 3 Soaking salts Drain opener Antacid 4 Vinegar 5 Ammonia 6 Salt 7 Shampoo 8 Baking Soda 9 Hydrogen peroxide Concrete cleaner Bleach 1 2 10 11 12 Usage Name of main component in substance Formula of main component in substance Hazard or Warning Root and algae killer Conclusion: True or False 1) Warning labels occur mainly on substances that are used for cooking. ________ 2) NaCl and NaHCO3 are edible compounds used in cooking. __________________ 3) Sodium hypochlorite is used for soaking sore feet. ________________________ 4) Magnesium sulfate heptahydrate is used to bleach material. ________________ 5) The compound listed first on the ingredient list is the main component in that substance. ________________________________________________________ 6) The main component in shampoo is water. ______________________________ 7) Household substances can be classified as acidic, basic or neutral. ___________ 8) Ammonia, antacids and aspirin are acidic compounds. _____________________ 9) Antacids can contain OH-1, CO3-2, HCO3-1 ions. ___________________________ 10)Table salt and baking soda both contain a sodium ion. _____________________ © DY Teacher Friendly Chemistry Introduction to Gas Laws Lab NAME:______________________________DATE:_____________PERIOD:_______ Background: In a gas, particles are spread far apart; therefore a gas takes up more volume than a solid or a liquid. For example, water in the form of steam takes up about 2000 times the volume that the same amount of water does in liquid form. There are many formulas to describe the behavior of a gas under certain conditions. Boyle’s Law, PV=k, states that the pressure is inversely proportional to the volume. Charles’s Law, V/T =k, states that volume is directly proportional to the temperature. Gay-Lussac’s Law, P/T =k, states that pressure is directly proportional to the temperature. Relationships that are directly proportional produce a straight line graph, while inversely proportional relationships produce a curve. Applying these laws to compare gases under two different sets of conditions gives the formulas: P1V1=P2V2 , V1/T1=V2/T2 , P1/T1 =P2/T2. These three laws together give the Combined Gas Law: P1V1/T1 =P2V2/T2. Procedure & Observations: Part 1 1) Obtain a large beaker (600-1000 mL) and fill 3/4 full of tap water. 2) Obtain an aluminum can and add 7-10 milliliters of water. 3) Place the can on a heating set up (hotplate or wire gauze/ring stand) and heat until a steady stream of steam flows out of the can. 4) Using beaker tongs, grab the aluminum can near the bottom of the can and quickly turn it upside down into the beaker of water. Observation: When the can was heated, the water turned to ___________, which takes up ________ (more/less) volume than liquid water. When the can was inverted into the water this created a closed system. The temperature inside the can ___________ (increased/decreased), causing the steam to change from gas state to ______________state. A partial vacuum was created causing the pressure inside the can to be ______________ (greater/less) than the pressure outside the can. Part 2 1) Obtain a small balloon filled with air. Submerge the balloon in a large beaker of ice water and hold for 3 minutes. Use beaker tongs to keep the balloon submerged. Observe. 2) Transfer balloon to large beaker of hot water and submerge for 3 minutes. Observe. Observation: As the water temperature increased, the volume of the balloon ______________. This is an example of _____________ Law. © DY Teacher Friendly Chemistry Part 3 1) Obtain a 250-mL Erlenmeyer flask and place 15-20 milliliters of water inside. 2) Place the flask onto a heating setup (hotplate or wire gauze/ring stand) and heat until a steady stream of steam comes out. DO NOT let the water boil away. 3) Take the flask off of the gauze using flask tongs. 4) While holding onto the neck of the flask using flask tongs, have a lab partner stretch the mouth of a large balloon over the mouth of the flask. Make sure the balloon is centered on the opening of the flask. This creates a closed system. 5) Wait 2-3 minutes and observe. Then place the flask into a beaker of ice water. Observation: Placing the balloon over the mouth of the flask created a __________ system. As the ______________ in the flask dropped the steam turned to water. Since water in the liquid state takes up less _____________ than water in the gas state, a partial vacuum was created. The greater ____________ outside of the flask pushed the balloon inside. Part 4 1) Obtain a 1000 mL beaker / candle set-up. 2) Fill the beaker with water until the water level is halfway up the candle. Light the candle. 3) Carefully invert a 1000 mL Erlenmeyer flask over the candle. Observe both candle and the water level. Observation: Propose an explanation: Conclusion: 1) Give the name of the law that relates pressure to volume. __________________ 2) Give the name of the law that relates volume to temperature._______________ 3) The condensing of steam in a closed system creates a partial ______________. 4) If the volume of a gas is cut by 1/2, the pressure will _____________________ (increase/decrease) by a factor of _________ (2, 1/2) times. 5) If the temperature of a gas is doubled, the volume of the gas will ____________ (increase/decrease) by a factor of ___________ (2, 1/2) times. 6) If the temperature of a gas is tripled, the pressure of the gas will ____________ (increase/decrease) by a factor of _________ (3, 1/3) times. 7) Graphing pressure vs. volume would produce a _______________. 8) Graphing volume vs. temperature would produce a _____________ line. © DY Teacher Friendly Chemistry Teacher Notes: Introduction to Gas Laws Lab At each lab station: Two Large beakers (600mL or 1000mL) Aluminum can Hotplate or wire gauze, ring stand, burner and striker Beaker tongs Small filled balloon-must be small enough to fit in large beakers 250-mL flask Flask tongs Medium size balloon 1000-mL flask Candle set-up: A 1000-mL beaker with a candle in the center with aluminum foil surrounding the base of the candle to keep it stable and centered. At a central location: Container of ice Lighter-This item may be best if kept with the teacher and the teacher comes around and lights each candle. Teaching Tips: This lab is a series of demonstrations that were put together for the student’s enjoyment. The students are surprised by the can being crushed and will many times ask for another can to repeat the experiment. This lab will take the student about 50 minutes to complete. © DY Teacher Friendly Chemistry Introduction to Gas Laws Lab NAME:______________________________DATE:_____________PERIOD:_______ Background: In a gas, particles are spread far apart; therefore a gas takes up more volume than a solid or a liquid. For example, water in the form of steam takes up about 2000 times the volume that the same amount of water does in liquid form. There are many formulas to describe the behavior of a gas under certain conditions. Boyle’s Law, PV=k, states that the pressure is inversely proportional to the volume. Charles’s Law, V/T =k, states that volume is directly proportional to the temperature. Gay-Lussac’s Law, P/T =k, states that pressure is directly proportional to the temperature. Relationships that are directly proportional produce a straight line graph, while inversely proportional relationships produce a curve. Applying these laws to compare gases under two different sets of conditions gives the formulas: P1V1=P2V2 , V1/T1=V2/T2 , P1/T1 =P2/T2. These three laws together give the Combined Gas Law: P1V1/T1 =P2V2/T2. Procedure & Observations: Part 1 1) Obtain a large beaker (600-1000 mL) and fill 3/4 full of tap water. 2) Obtain an aluminum can and add 7-10 milliliters of water. 3) Place the can on a heating set up (hotplate or wire gauze/ring stand) and heat until a steady stream of steam flows out of the can. 4) Using beaker tongs, grab the aluminum can near the bottom of the can and quickly turn it upside down into the beaker of water. Observation: The can was crushed when placed into the beaker of water. When the can was heated, the water turned to __steam____, which takes up _more___ (more/less) volume than liquid water. When the can was inverted into the water this created a closed system. The temperature inside the can _decreased__ (increased/decreased), causing the steam to change from gas state to __liquid_____ state. A partial vacuum was created causing the pressure inside the can to be _less______ (greater/less) than the pressure outside the can. Part 2 1) Obtain a small balloon filled with air. Submerge the balloon in a large beaker of ice water and hold for 3 minutes. Use beaker tongs to keep the balloon submerged. Observe. 2) Transfer balloon to large beaker of hot water and submerge for 3 minutes. Observe. Observation: The balloon expanded in hot water. The balloon volume was smallest in cold water. As the water temperature increased, the volume of the balloon __increased___. This is an example of _Charles’s___ Law. © DY Teacher Friendly Chemistry Part 3 1) Obtain a 250-mL Erlenmeyer flask and place 15-20 milliliters of water inside. 2) Place the flask onto a heating setup (hotplate or wire gauze/ring stand) and heat until a steady stream of steam comes out. DO NOT let the water boil away. 3) Take the flask off of the gauze using flask tongs. 4) While holding onto the neck of the flask using flask tongs, have a lab partner stretch the mouth of a large balloon over the mouth of the flask. Make sure the balloon is centered on the opening of the flask. This creates a closed system. 5) Wait 2-3 minutes and observe. Then place the flask into a beaker of ice water. Observation: The balloon collapsed and then inverted into the flask lining the inside of the flask. Placing the balloon over the mouth of the flask created a __closed__ system. As the _temperature__ in the flask dropped the steam turned to water. Since water in the liquid state takes up less __volume_____ than water in the gas state, a partial vacuum was created. The greater _pressure__ outside of the flask pushed the balloon inside. Part 4 1) Obtain a 1000 mL beaker / candle set-up. 2) Fill the beaker with water until the water level is halfway up the candle. Light the candle. 3) Carefully invert a 1000 mL Erlenmeyer flask over the candle. Observe both candle and the water level. Observation: The candle went out and the water level increased and went above the candle. Propose an explanation: Answers will vary from running out of oxygen to pressure greater outside of flask. Conclusion: 1) Give the name of the law that relates pressure to volume. ___Boyles_________ 2) Give the name of the law that relates volume to temperature. _Charles’s______ 3) The condensing of steam in a closed system creates a partial __vacuum______. 4) If the volume of a gas is cut by 1/2, the pressure will _________increase_____ (increase/decrease) by a factor of ___2_____ (2, 1/2) times. 5) If the temperature of a gas is doubled, the volume of the gas will __increase__ (increase/decrease) by a factor of _____2_____ (2, 1/2) times. 6) If the temperature of a gas is tripled, the pressure of the gas will __increase__ (increase/decrease) by a factor of ____3____ (3, 1/3) times. 7) Graphing pressure vs. volume would produce a __curve________. 8) Graphing volume vs. temperature would produce a _straight__ line. © DY Teacher Friendly Chemistry Introduction to Gas Laws Lab Quiz NAME:______________________________DATE:_____________PERIOD:_______ True (A) or False (B) Place either an “A” or a “B” in the blank provided. 1) _____Boyle’s Law states that pressure is inversely proportional to volume. 2) _____Charles’s Law states that volume and temperature are directly proportional. 3) _____Gay-Lussac’s Law states that pressure and temperature are directly proportional. 4) If the pressure is increased by a factor of 3 times then the volume will increase by a factor of 3 times. 5) _____If the temperature is increased by a factor of 2 times then the pressure will increase by a factor of 2 times. 6) _____Decreasing the volume of a container by ½ will double the pressure. 7) _____A graph of volume vs. temperature will produce a curve. 8) _____A graph of an inversely proportional relationship will produce a straight line. 9) _____When steam condenses in a closed container a partial vacuum is created. 10)_____The can was crushed by atmospheric pressure. 11)_____A balloon placed into cold will increase in volume. © DY Teacher Friendly Chemistry Introduction to Gas Laws Lab Make-up NAME:______________________________DATE:_____________PERIOD:_______ Background: In a gas, particles are spread far apart; therefore a gas takes up more volume than a solid or a liquid. For example, water in the form of steam takes up about 2000 times the volume that the same amount of water does in liquid form. There are many formulas to describe the behavior of a gas under certain conditions. Boyle’s Law, PV=k, states that the pressure is inversely proportional to the volume. Charles’s Law, V/T =k, states that volume is directly proportional to the temperature. Gay-Lussac’s Law, P/T =k, states that pressure is directly proportional to the temperature. Relationships that are directly proportional produce a straight line graph, while inversely proportional relationships produce a curve. Applying these laws to compare gases under two different sets of conditions gives the formulas: P1V1=P2V2 , V1/T1=V2/T2 , P1/T1 =P2/T2. These three laws together give the Combined Gas Law: P1V1/T1 =P2V2/T2. Procedure & Observations: Part 1 1) Obtain a large beaker (600-1000 mL) and fill 3/4 full of tap water. 2) Obtain an aluminum can and add 7-10 milliliters of water. 3) Place the can on a heating set up (hotplate or wire gauze/ring stand) and heat until a steady stream of steam flows out of the can. 4) Using beaker tongs, grab the aluminum can near the bottom of the can and quickly turn it upside down into the beaker of water. Observation: The can was crushed when it was inverted into the beaker of water. When the can was heated, the water turned to ___________, which takes up ________ (more/less) volume than liquid water. When the can was inverted into the water this created a closed system. The temperature inside the can ____________ (increased/decreased), causing the steam to change from gas state to ____________state. A partial vacuum was created causing the pressure inside the can to be ______________ (greater/less) than the pressure outside the can. Part 2 1) Obtain a small balloon filled with air. Submerge the balloon in a large beaker of ice water and hold for 3 minutes. Use beaker tongs to keep the balloon submerged. Observe. 2) Transfer balloon to large beaker of hot water and submerge for 3 minutes. Observe. Observation: The volume decreased in the ice water and increased in the hot water. As the water temperature increased, the volume of the balloon ______________. This is an example of _____________ Law. © DY Teacher Friendly Chemistry Part 3 1) Obtain a 250-mL Erlenmeyer flask and place 15-20 milliliters of water inside. 2) Place the flask onto a heating setup (hotplate or wire gauze/ring stand) and heat until a steady stream of steam comes out. DO NOT let the water boil away. 3) Take the flask off of the gauze using flask tongs. 4) While holding onto the neck of the flask using flask tongs, have a lab partner stretch the mouth of a large balloon over the mouth of the flask. Make sure the balloon is centered on the opening of the flask. This creates a closed system. 5) Wait 2-3 minutes and observe. Then place the flask into a beaker of ice water. Observation: The balloon was pushed into the flask and lined the inside of the flask. Placing the balloon over the mouth of the flask created a __________ system. As the ______________ in the flask dropped the steam turned to water. Since water in the liquid state takes up less _____________ than water in the gas state, a partial vacuum was created. The greater ____________ outside of the flask pushed the balloon inside. Part 4 1) Obtain a 1000 mL beaker / candle set-up. 2) Fill the beaker with water until the water level is halfway up the candle. Light the candle. 3) Carefully invert a 1000 mL Erlenmeyer flask over the candle. Observe both candle and the water level. Observation: The flame went out and then the water level inside the flask increased and went above the candle. Propose an explanation: Conclusion: 1) Give the name of the law that relates pressure to volume. __________________ 2) Give the name of the law that relates volume to temperature._______________ 3) The condensing of steam in a closed system creates a partial ______________. 4) If the volume of a gas is cut by 1/2, the pressure will _____________________ (increase/decrease) by a factor of _________ (2, 1/2) times. 5) If the temperature of a gas is doubled, the volume of the gas will ____________ (increase/decrease) by a factor of ___________ (2, 1/2) times. 6) If the temperature of a gas is tripled, the pressure of the gas will ____________ (increase/decrease) by a factor of _________ (3, 1/3) times. 7) Graphing pressure vs. volume would produce a _______________. 8) Graphing volume vs. temperature would produce a _____________ line. © DY Teacher Friendly Chemistry