State of MatterState of MatterSolid is fixed shapeLiquid takes on the shape ofits container.Gas has neither a fixed shapenor a fixed volumeRecall
DENSITYDENSITYQ) Which weighs more:-A kilogram of feathers or a kilogram of iron?
What is Density?What is Density?Density is the Mass per unitVolumeWood Water Iron1 cm31 cm3 1 cm3If you take the same volume of different substances,then they will weigh different amounts.0.50 g 1.00 g 8.00 gQ) Which has the greatest mass and therefore the most dense?IRON
Density =MassVolumeg or kgcm3or m3gcm-3or kgm-3 ρ = mVExample:Q) Liquid water has a density of 1000kgm-3, while ice has densityof 920kgm-3. Calculate the volume occupied by 0.25kg of each.Density Equation:mVρV = m = 0.25 = 0.000250m3ρ 1000V = m = 0.25 = 0.000272m3ρ 920
DENSITY OF A REGULAR SOLIDDENSITY OF A REGULAR SOLID Find the Mass ofFind the Mass ofthe solid on athe solid on abalance.balance. Measure theMeasure thethree lengths andthree lengths andcalculate thecalculate theVolume.Volume.(ie V = l x w x h )(ie V = l x w x h ) Calculate theCalculate theDensity.Density.l = 4.0 cmw= 2.0 cmh=3.0 cmρ = m = 240 =10.0 g/cm3V 24m = 240 g
DENSITY OF AN IRREGULAR SOLIDDENSITY OF AN IRREGULAR SOLID Find the Mass of the solidFind the Mass of the solidon a balance.on a balance.Fill the Measuring CylinderFill the Measuring Cylinderwith Water to a knownwith Water to a knownVolume.Volume. Add the Object.Add the Object. Work out the Volume ofWork out the Volume ofWater that is displaced.Water that is displaced. Calculate the Density.Calculate the Density.50 cm380 cm3m = 360 gρ = m = 360 =12.0 g/cm3V 30
DENSITY OF AN IRREGULAR SOLIDDENSITY OF AN IRREGULAR SOLID OR use a Eureka Can to find the Volume.OR use a Eureka Can to find the Volume. Find the mass of the solid onFind the mass of the solid ona balance.a balance.Add water until justAdd water until justoverflowing.overflowing. Place a Measuring CylinderPlace a Measuring Cylinderunder the spout.under the spout. Add the Object.Add the Object. Collect the Water and read offCollect the Water and read offthe Volume.the Volume.Calculate DensityCalculate Densitym = 440 g40.0 cm3ρ = m = 440 =11.0 g/cm3V 40
DENSITY OF A LIQUIDDENSITY OF A LIQUID Find the Mass of an emptyFind the Mass of an emptyMeasuring Cylinder.Measuring Cylinder. Add a certain Volume of Liquid.Add a certain Volume of Liquid. Find the Mass of the MeasuringFind the Mass of the MeasuringCylinder and LiquidCylinder and Liquid Calculate the Mass of Liquid.Calculate the Mass of Liquid. How?How? Calculate Density of Liquid.Calculate Density of Liquid.Mass of Liquid = Mass of Measuring Cylinder and Liquid – Massofempty Measuring Cylinder25.0 g20.0 cm345.0 g45 – 25 = 20 gρ = m = 20 =1.00 g/cm3V 20
DENSITY OF A GASDENSITY OF A GAS Remove the air fromRemove the air froma flask of a knowna flask of a knownVolume, using aVolume, using avacuum pump.vacuum pump. Find its Mass.Find its Mass. Add the gas to beAdd the gas to betested.tested. Reweigh.Reweigh. The difference is theThe difference is theMass of gas.Mass of gas. Calculate Density.Calculate Density.To vacuum flask1000 cm3m(glass)=150.0 gm(total)=170.0 gρ = m = 20 =0.0200 g/cm3V 1000170 -150 = 20.0g
Problem of DensityProblem of Density2. What is the density of a piece ofwood that has a mass of 25.0grams and a volume of 29.4 cm3?1. A piece of wood that measures 3.0 cm by 6.0cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? Would the piece of wood float in water? (volume = L x W x H)
3. A cup of gold colored metal beads was3. A cup of gold colored metal beads wasmeasured to have a mass 425 gramsmeasured to have a mass 425 grams.. By waterBy waterdisplacement, thedisplacement, the volumevolume of the beads wasof the beads wascalculated to be 48.0 cmcalculated to be 48.0 cm33.. Given the followingGiven the followingdensities, identify the metaldensities, identify the metal..GoldGold:: 19.3 g19.3 g//mLmLCopperCopper:: 8.86 g8.86 g//mLmLBronzeBronze:: 9.87 g9.87 g//mLmL
4. The4. The volumevolume of aof a solutionsolutionwas measured in a graduatwas measured in a graduateded cylindercylinder (shown above). I(shown above). If thef the massmass ofof solutionsolution is meis measured to be 60.75 grams,asured to be 60.75 grams,what is thewhat is the densitydensity of the solof the solution?ution?