Reading the Graduated Cylinder And All about the

Reading the Graduated Cylinder And All about the Meniscus

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• Graduated cylinders are used to measure the volume of liquid and are available in many different sizes. The SI unit for the graduated cylinders is the m. L.

Reading the Graduated Cylinder • Liquids in glass and some plastic containers curve at the edges • This curve is called the MENISCUS • LOOK FOR IT ON YOUR GRADUATED CYLINDER

Reading the Graduated Cylinder • Your eye should be level with the top of the liquid You should read to the bottom of the MENISCUS

Steps in brief… • Step 1: Determine the scale increment: – A. Pick any two numbers – B. Substract the two numbers – C. Count number of lines between the two numbers (include top line) – D. Divide the number from B the number from C • Step 2: Use the graduations to find all certain digits – Add Answer from Step 4 to each line up until the meniscus.

Practice Reading the Graduated Cylinder • What is this reading? 18. 0 ml

Practice Reading the Graduated Cylinder • What is this reading? 36. 5 ml

Practice Reading the Graduated Cylinder • What is this reading? 42. 9 ml

Practice Reading the Graduated Cylinder • What is this reading? 47. 0 ml

Practice Reading the Graduated Cylinder • What is this reading? 61. 2 ml

Looking at a 10 m. L cylinder • What is the volume you should record for the solution in the image to the right? – 6. 31 m. L correct – 6. 3 incorrect – WHY?

Looking at a 25 m. L cylinder • What is the volume you should record for the solution in the image to the right?

Looking at a 100 m. L cylinder • What is the volume you should record for the solution in the image to the right? – 52. 8 m. L correct – 53 m. L incorrect – Why?

Reading the Volume from a Graduated Cylinder • Determine the gradation markings on the GC. • Determine the volume contained in a graduated cylinder by reading the bottom of the meniscus at eye level. • Read the volume using all certain digits and one uncertain digit. – Certain digits are determined from the calibration marks on the cylinder. – The uncertain digit (the last digit of the reading) is estimated.