DENSITY and TEMPERATURE

It’s time to get at that work

Density

• DENSITY = MASS / Volume• d = m / v• Density is an INTENSIVE property. Why?

Density

• High density –Molecules are closer together• Low Density – Molecules are further apart

Density - SOLVE

• Gold (Au) is a substance that is chemically unreactive. A piece of gold ingot (molded material) has a mass of 301g and a volume of 15.6cm3. Calculate the density.

• d = m / v

Set up the equation

• d = m / v• d = 301g / 15.6cm3

• d = 19.29487179 g/cm3

• d = 19.3 g/cm3

Density Solve again!!

• Mercury (Hg) is the only metal that is liquid at room temperature. It has a density of 13.6 g/mL. Calculate the mass of 5.50 mL of the liquid.

Density

• d = m / v• 13.6 g/mL = 5.50 g / v

What is the rule if our variable is in the denominator?

Density

• CROSS MULTIPLY THE VARIABLE FIRST!!!!• (v) 13.6 g/mL = 5.50 g (v) v(v) 13.6 g/mL = 5.50 g 13.6 g/mL 13.6 g/mLV = 0.404411765 gV = 0.404 g

Temperature

• Temperature is also an intensive property• IT is NOT a measurement of ‘hot’ or ‘cold’• Temperature is a measurement of kinetic

energy (mass in motion)

• When there is less kinetic energy, substances freeze• When there is more kinetic energy, substances heat

up

Temperature

Fahrenheit (F°)Celsius (C°)Kelvin (k)Kelvin is an absolute numberK = C° + 273.15C° = (F° - 32°) X 5/9F° = 9/5 X (C° + 32°)c °= k – 273.15

THE DENSITY LAB DAY 1

• 1) Measure the Beaker• 2) Measure the volume of water• 3) POUR water into beaker• 4) Measure water + beaker• 5) EXPERIEMENT WITH EGG• 6) Add salt• 7) Measure SALTwater + beaker, and VOLUME• 8) EXPERIMENT WITH EGG AGAIN!!!!!

The density of Aluminum is 2.7 g/mL. The volume of a particular sample is 3.0 mL. Calculate to find the mass.

• d = m / v• 2.7 g/mL = m / 3.0 mL• m = 8.1 g

An object has a mass of 7.5 g and a volume of 5.0 mL. Solve to find the density of this object.

• d = m / v• d = 7.5g / 5.0 mL• d = 1.5 g/mL

• 435°F = _____C°• C° = (F° - 32°) X 5/9• C° = (435° - 32°) X 5/9• C° = (403°) X 5/9• C° = 2015 /9• C° = 224°

K = C° + 273.15

• 31°C = ______k• K = C° + 273.15• K = 31° + 273.15• K = 304.15k

F° = 9/5 X (C°) + 32°

• -269°C=_____F°• F° = 9/5 X (C°) + 32°• F° = 9/5 X (-268°) + 32°• F° = 9/5 X -236°• F° = -425.8°

K = C° + 273.15

• 234.3k = _____C° • K = C° + 273.15• 234.3 = C° + 273.15• 234.3 – 273.15 = C° + 273.15 – 273.15• C° = -38.85°

Does the addition of SALT to the water make a difference? Why or Why not?

• Why do you think the egg sank or floated in the salt water in comparison to the regular water?

• What property of the egg caused the egg to sink or float? Is this property extensive or intensive? Why or Why not?

DENSITY LAB DAY 2

• Measure the volume of the wooden block• Measure the mass of the wooden block• Measure the beaker• Measure the volume of the water• Measure the mass of the water• EXPERIMENT with the block