Their accuracy is partly dependent on their size which comes in a range of 12 to 24 inches. The graduations on a pipette can measure liquids within a 0.
On the whole, all the different glassware have a level of accuracy that works in specific cases. They key to chemistry experiments is to use high-quality products that are tolerable to the hazardous chemicals in use and provide accurate readings. For over 40 years, Lab Pro has been committed to delivering the most accurate glassware for measuring volume to our customers worldwide.
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The second method was more precise because volume was calculated using density, the temperature of water, and a digital balance. Based on accuracy, assign each piece of glassware appropriate uses and state evidence for your choice. If you need to measure other volumes besides those on volumetric flasks, then the graduated cylinder is the best tool. The beaker is pretty accurate, and you can easily stir and heat chemicals in it. I would not use a flask to measure volume given the large percent error.
Accurate glassware : volumetric pipetPrecise glassware : volumetric pipet2 Each piece of glassware typically will be labeled either TC to contain or TD to deliver. Using the TD notion, the liquid will be accurate when transferred, however when using the TC notion, the liquid will not be accurate when delivered to another container. For each task, select either the volumetric flask, beaker, pipe, or graduate cylinder and explain why it would be the best choice.
Archive "Always start out with a larger pot than what you think you need. Contents 1. Get general information, care guides, and product information here.
Brush up on the latest instructional strategies and pedagogy with information from our teaching partners, instructional designers, and academic consultants. Feeling the pinch from the current economy? Carolina understands. Home » Interdisciplinary » Accuracy of Glassware. Many science classes begin with an overview of equipment. Students memorize the names of laboratory glassware and their functions but rarely determine accuracy or relate glassware accuracy to function.
In this activity, students employ density calculations to establish the accuracy of several common pieces of laboratory glassware and make a claim relating the accuracy of a piece of glassware to its designated purpose. Accuracy is defined as how close a measurement is to the true or standard value. Students compare accuracy values for different pieces of glassware using percent error calculations and use percent error as evidence for justifying a claim relating glassware accuracy to use.
Students may have seen wet or liquid and dry measuring cups in the kitchen and wondered if a wet cup is equal in volume to a dry cup. This quick demonstration is an easy segue into the concept of laboratory glassware accuracy.
Obtain dry and liquid kitchen measuring cups. The volume of the dry cup does not matter. Fill the dry cup with water, and then pour the water into the liquid measuring cup. Ask students to observe. Repeat the demonstration with a dry substance—flour, sugar, rice, and small beans are good examples. Ask students to make a claim about the accuracy of the measuring cups.
Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a newsolution to better meet the criteria for success.
Remind students to be mindful of where they place glassware. Have a broom, dust pan, and a container for broken glassware available. Remind students not to pick up broken glass with their hands. Group glassware prior to the activity. Make certain the volume of water the volumetric flask holds will fall between the graduations on the other pieces of glassware.
No chemical or waste disposal is necessary. Dispose of any broken glass in the appropriate container. Based on the data collected, rank the 4 pieces of glassware from most accurate to least accurate. Explain your reasoning. Student answers will vary, but they should notice higher accuracy for the volumetric flask and graduated cylinder. Using individual data and the density of water table, calculate the actual volume of water in each piece of glassware.
Average the individual actual volumes for each piece of glassware and place the values in the table. Based on percent error only, rank the glassware from most accurate to least accurate. Use your data to explain your ranking. The volumetric flask had the lowest percent error 0. The graduated cylinder and beaker were similar in percent error 2. Both were small, so they are fairly accurate.
The flask had the highest percent error How do the 2 methods of determining accuracy compare? Were the results the same or different? The rankings were the same. The first method provided a less precise ranking of glassware since the volume of water had to be estimated for every piece of glassware but the volumetric flask.
The second method was more precise because volume was calculated using density, the temperature of water, and a digital balance. Based on accuracy, assign each piece of glassware appropriate uses and state evidence for your choice.
For example, which pieces should be used for measurement, and which should not be used for measurement? The volumetric flask is the most accurate, but it only measures 1 volume—in this case, mL. If you need to measure other volumes besides those on volumetric flasks, then the graduated cylinder is the best tool. The beaker is pretty accurate, and you can easily stir and heat chemicals in it. I would not use a flask to measure volume given the large percent error. If volume only had to be estimated, a flask would be OK.
It is also good for mixing and heating. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, these products. We use cookies to provide you with a great user experience. By using our site, you accept our use of cookies. You can review our cookie and privacy policy here. Login or Register My Account Login or register now to maximize your savings and access profile information, order history, tracking, shopping lists, and more.
Login Create an Account. Call: International Ordering Information. My Cart Your Shopping Cart is currently empty. Lab glassware you're almost guaranteed to encounter includes flasks, beakers, pipets and graduated cylinders.
Most serve as tools to measure out quantities of liquids; some are roughly accurate, others have great accuracy. Knowing the differences between the kinds of glassware available to you will help you design and carry out experiments more efficiently. Common lab glassware includes flasks, beakers, pipets, burets and graduated cylinders. Each is suited for storing, examining, and measuring liquids for different kinds of laboratory activities. Erlenmeyer flasks have a narrow neck over a conical base, while beakers are basically large open-mouthed glass jars with a lip and spout for pouring.
Graduated cylinders are tall cylinders with a spout to pour liquids; they have hash marks on the side to measure the volume of their contents. Volumetric flasks have a flat-bottomed bulb and a long, narrow neck with a hash mark along the side to indicate the point at which the flask is full. Burets are long, tall cylinders--generally much narrower and taller than graduated cylinders--with hash marks to measure volume and a stopcock at the bottom; the stopcock can be turned to allow the contents to drip out.
Pipets are long narrow glass tubes with a bulb in the center, a hash mark to indicate when they are full, and a narrow tip.
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