Calculating Density Class Practice

The Formulas To calculate the volume of a regular shaped solid you must multiply length X width X height Density = mass ÷ volume also written out Density = mass/volume Mass = density X volume Volume = mass ÷ density When ever the # for mass is given (some version of grams) grams goes in the calculator first because she was born first (hint hint). No matter if you are finding volume or density.

Step One You must first read the question to see if they want you to find mass, volume or density. If it’s volume they will give the mass and the density If it’s density the question will give you the mass in g and the volume in mL or cm3. (The answer for density will be in g/cm3 for solids and g/mL for liquids). If it’s mass the question will give you the density and the volume.

Step Two Write out the equation Mass = #density X #volume Density = #mass ÷ #volume Volume = #mass ÷ #density Then do the math. Let’s try a few. You can use the notes you just took.

Try number 1 A student measures the mass of an 8 cm3 block of brown sugar to be 12g. What is the density of the brown sugar? The mass and the volume are given. What does the question ask you to calculate? Write the math equation you will need to solve on your board. Now do the math and write the answer on your board.

Try Number 2 A chef fills a container up to the 50 mL line with 43g of oil. What is the density of the oil? First write on your board the word for what the question wants you to find. Now write out the equation you will solve Now do the math and write the answer on your board.

Try Number 3 If a perfect cube with a mass of 176g measures 4cm in every direction what is the density of the cube. What two things must you know to find the density of an object? How do you find the volume of a regular shaped solid? Write out the math to find the volume of this solid. Then do the math. Now find the density using the mass that was given and volume you calculated. Write that on your board.

Try Number 4 Calculate the mass of a liquid with a density of 2.5 g/mL and a volume of 15 mL. What does the question ask you to find? What is the basic equation for finding this value? What is the math equation for finding that value for THIS question? Now do the math and write your answer on your board

Try Number 5 A block has a mass of 43 g and a density of 1.3 g/cm3. What is the volume of that block? What is the basic equation for finding volume? What is the equation for finding the volume of THIS block? Now do the math and write your answer on your board.

Try Number 6 The density of a rock is .87 g/cm3 and it’s mass is 32 grams. What is the volume of the rock? What is the problem asking you to find? What is the basic equation for finding that? What is the equation for finding that for THIS rock? Do the math and write your answer on your board.

Try Number 7 A unknown liquid has a density of 3.2 g/mL and a volume of 42 mL. What is the mass of the liquid? What is the problems asking you to find? What is the equation for finding that? What is the equation for finding that for THIS liquid? Now do the math and write your answer on your board.

Try Number 8 An unknown solid has a volume of 36 cm3 and a density of 1.6 g/cm3. What is the mass of the solid? What is the question asking you to find? What is the basic equation for finding that answer? What is the equation for finding that for THIS solid? Now do the math and write your answer on your board.

Try Number 9 A plastic car has a density of .67 g/cm3 and a volume of 11 cm3. What is the mass of the plastic car? What is the question asking you to find? What is the basic equation for finding that? What is the equation for finding that for THIS plastic car? Now do the math and write your answer on your board.

Table of Densities Solid Type Density g/cm3 Marble 2.56 Copper 8.92 Quartz 2.64 Gold 19.32 Diamond 3.52 Platinum 21.4

Try Number 10 While digging in the backyard, you find an old coin. Its mass is 26.76 g and its volume is 3 cm3. What is the old coin made from? First, what must you find to use the chart to find out what it is? What is the basic equation for finding that? What is the equation for finding that for THIS coin? Do the math and write your answer on your board.

What was your coin made of? Table of Densities Solid Type Density g/cm3 Marble 2.56 Copper 8.92 Quartz 2.64 Gold 19.32 Diamond 3.52 Platinum 21.4

Try Number 11 You think you have found a diamond. Its mass is 5.28g and its volume is 2 cm3. What do you need to know about this thing to use the chart to see what it really is? What is the basic equation for finding that out? What is the equation for that for THIS item? Now do the math and write it on your board.

What was your item made from? Table of Densities Solid Type Density g/cm3 Marble 2.56 Copper 8.92 Quartz 2.64 Gold 19.32 Diamond 3.52 Platinum 21.4

Try number 12 There is a paper weight on the teacher’s desk. Its measurements are 3 cm by 4 cm by 6 cm. The paper weight has a mass of 184.32 g. What do you have to know to calculate density? What is the math you must do to find the volume for this block? Write your answer on your board. Now what is the equation for finding the density of THIS paperweight? Do the math and write your answer on your board.

What is the paperweight made of? Table of Densities Solid Type Density g/cm3 Marble 2.56 Copper 8.92 Quartz 2.64 Gold 19.32 Diamond 3.52 Platinum 21.4

Try Number 13 You find a ring with a mass of 107 g. You fill a graduated cylinder up with 10 mL of water and put the ring in the cylinder. The water rises up to the 15 mL mark. What is the volume of the ring? What is the density of the ring? Write your answer to both of those on your board.

What was the ring made of? Table of Densities Solid Type Density g/cm3 Marble 2.56 Copper 8.92 Quartz 2.64 Gold 19.32 Diamond 3.52 Platinum 21.4

Rank these on your board from least dense to most dense. Table of Densities Solid Type Density g/cm3 Marble 2.56 Copper 8.92 Quartz 2.64 Gold 19.32 Diamond 3.52 Platinum 21.4