Density Notes EQ: What is density?

A. Mass Measured in grams (g) Mass vs weight Depends on the attraction of gravity matter in the object

B. Volume Measured in cm3, mL, L, … Amount of space taken up by an object

Ways to Find Volume Measuring distance and use an equation

Ways to Find Volume 2. Water Displacement (Final volume – Initial volume)

Archimedes Principle https://www.youtube.com/watch?v=ijj58xD5fDI After immersion Fishing sinker 98.5 cm3 Thread Vfinal = 98.5 cm3 - Vinitial = 44.5 cm3 Vfishing sinker = 54.0 cm3 Before immersion Water 44.5 cm3 Archimedes Principle: water displacement method to find the volume of an irregularly shaped object. The volume the water level increased is equal to the volume of the submerged object. The most famous application of buoyancy is due to Archimedes of Syracuse around 250 BC. He was asked to determine whether the new crown that King Hiero II had commissioned contained all the gold that he had provided to the goldsmith for that purpose; apparently he suspected that the smith might have set aside some of the gold for himself and substituted less-valuable silver instead. According to legend, Archimedes devised the principle of the “hydrostatic balance” after he noticed his own apparent loss in weight while sitting in his bath. The story goes that he was so enthused with his discovery that he jumped out of his bath and ran through the town, shouting "eureka" to the bemused people. https://www.youtube.com/watch?v=ijj58xD5fDI

You Try Initial Final 68.0 mL 64.0 mL

You Try 4.0 mL Final – Initial = _______ 68.0 mL - 64.0 mL 4.0 mL

C. Density Mathematical Definition: amount of mass in a given volume

C. Density Particle Definition: A measure of how tightly spaced matter is

C. Density Density is a physical property that can be used to identify a substance Substance Density (g/mL) Aluminum 2.70 Titanium 4.54 Zinc 7.13 Tin 7.31 Iron 7.87 Nickel 8.90 Copper 8.96 Silver 10.50 Lead 11.35 Mercury 13.55 Gold 19.30

D. Density Practice A piece of metal with a mass of 1.58 grams was placed into a graduated cylinder filled with 25.65 ml of water and the water level rose to 25.87 ml.

Problem solving in Chemistry GUESS G- Givens U- Unknowns E- Equation S- Substitute S – Solve   Don’t forget to round your answer to the correct number of significant Figures

D. Density Practice D = m V D = A piece of metal with a mass of 1.58 grams was placed into a graduated cylinder filled with 25.65 ml of water and the water level rose to 25.87 ml. Calculate the density and identify the metal. Givens Work m = 1.58 g D = m V = 25.87 mL V - 25.65 mL D = 1.58 g 0.22 mL = 7.1818 g/mL 0.22 mL D = ? = 7.2 g/mL identity?

D. Density Practice D = m V D = Substance Density (g/mL) Aluminum 2.70 Titanium 4.54 Zinc 7.13 Tin 7.31 Iron 7.87 Nickel 8.90 Copper 8.96 Silver 10.50 Lead 11.35 Mercury 13.55 Gold 19.30 Givens Work m = 1.58 g D = m V = 25.87 mL V - 25.65 mL D = 1.58 g 0.22 mL = 7.1818 g/mL 0.22 mL D = ? = 7.2 g/mL identity? Zinc

D. Density Practice D = m D V = m 1 V 1 m = A substance has a density of 4.50 g/cm3. What is the mass of 6.00 cm3 of this substance? Givens Work D = 4.50 g/cm3 D = m D V = m 1 V = 6.00cm3 V 1 m = ? m = 4.50 g/cm3 6.00cm3 x = 27 g = 27.0 g

Density Practice D = m V = ? ___ 1 v V = m D D V = m ___ D ___ D A substance has a density of 5.38 g/cm3. What is its volume if the total mass of the sample is 2.33 g? Rearrange the equation to solve this problem. D = m V = ? ___ 1 v V = m D D V = m ___ D ___ D

Density Practice D= m= V= D = m V = m D 1 V 1 D V = A substance has a density of 5.38 g/cm3. What is its volume if the total mass of the sample is 2.33 g? Givens Work D= m= V= D = m V = m D 1 5.38 g/cm3 V 1 D 2.33 g =0.43308cm3 2.33 g V = 5.38 g/cm3 =0.433cm3 ?