Reading the Graduated Cylinder Reading vol notes R4

Calculating volume Find the LENGTH, WIDTH, & HEIGHT of the object Multiple the LENGTH, WIDTH, & HEIGHT Cube the units of measurement (cm^3) Example: Volume = 3 cm X 6 cm X 4 cm Volume = 72 cm^3 or 73 cubic centimeter cm

Reading the Graduated Cylinder Liquids in glass and some plastic containers curve at the edges Changing the diameter of the cylinder will change the shape of the curve This curve is called the MENISCUS

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

Reading a graduated cylinder’s volume From above meniscus WRONG!!!!! From below meniscus WRONG!!!!!

Reading a graduated cylinder’s volume From the side of the meniscus CORRECT!!!

Measuring Volume What causes the meniscus? A concave meniscus occurs when the molecules of the liquid attract those of the container. The glass attracts the water on the sides. Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gif Bottom Image: http://morrisonlabs.com/meniscus.htm

Practice Reading the Graduated Cylinder What is this reading? 18.0 ml

Practice Reading the Graduated Cylinder What is this reading? 36.5 ml

Take notes in to R4 starting here

Calculating volume Find the LENGTH, WIDTH, & HEIGHT of the object Multiply the LENGTH, WIDTH, & HEIGHT Cube the units of measurement (cm^3) Example: Volume = 3 cm X 6 cm X 4 cm Volume = 72 cm^3 or 72 cubic centimeter cm

Reading volume in a graduated cylinder 1. Figure out the intervals between the hash marks 2. Read the bottom of the meniscus

End of notes

Practice Reading the Graduated Cylinder What is this reading? 43 ml

Practice Reading the Graduated Cylinder What is this reading? 47.0 ml

Practice Reading the Graduated Cylinder What is this reading? 61 or 61.2 ml

What is the volume? Length = 3 cm Width = 2 cm Height = 4 cm

Reading volume

Extra slides

Measuring Volume We will be using graduated cylinders to find the volume of liquids and other objects. Read the measurement based on the bottom of the meniscus or curve. When using a real cylinder, make sure you are eye-level with the level of the water. What is the volume of water in the cylinder? _____mL What causes the meniscus? A concave meniscus occurs when the molecules of the liquid attract those of the container. The glass attracts the water on the sides. Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gif Bottom Image: http://morrisonlabs.com/meniscus.htm

Measuring Solid Volume http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/en/syllabus/unit14/new/testingmain1.htm We can measure the volume of irregular object using water displacement. Amount of H2O with object = ______ About of H2O without object = ______ Difference = Volume = ______ Click here for an online activity about volume. Choose Lessons  Volume & Displacement

Measuring volume of an irregularly-shaped object For example, if there is 85ml of water in a graduated cylinder and you add an object, then the volume of the water and the object is 92ml. What is the volume of the object? 92ml (volume of water with object submerged) -85ml (volume of just the water) 7ml (volume of object)