Extended Catalyst 10/18/10If you pour together liquids that do not mix they will form layers. Which liquid do you think will sink to the bottom?

Why?

rubbing alcohol corn syrup

honey vegetable oil water Objectives on next slide

1. Given the diagram showing identical levels of gas molecules in different containers, a reasonable inference could be made that there is a relationship between:

A. temperature and pressure B. volume and pressureC. temperature and density D. volume and temperature

2. The relationship between the variables in this diagram is best described as what type of relationship?

A. Direct B. proportional C. Inverse D. exponential

3. Given the information displayed in the diagram, which equation using the terms p (pressure), V (volume) and k (constant value) best describes the relationship between the variables?

A. V=p/k B. pV=kC. pk=V² D. k=p/V

ACT Practice Catalyst 10/18/10

Objective on next slide

Agenda & Objectives- 1 & 2Objectives:Determine relative densities of substances using layering information.  Determine density, mass, and volume of substances.

Agenda:

Density guided notes & activities

Homework:

Complete questions on back of guided notes

Agenda & Objectives- 4, 5 & 7Objectives:Determine relative densities of substances using layering information.  Determine density, mass, and volume of substances.

Agenda:Catalyst (7)Complete density guided notes (15)Independently complete back of guided notes (10)Density calculation practice (15)

Homework:Density problem worksheet

Liquid Layers

If you pour together liquids that don’t mix and have different densities, they will form liquid layers.

The liquid with the highest density will sink to the bottom.

The liquid with the lowest density will float on top.

Density is the measure the amount of stuff in a given space.

More scientifically, it is the amount of mass in a given volume

All substances have density including liquids, solids, and gases

What is Density?

“Compactness”

Low density

High Density

In terms of our density column….rubbing alcohol baby oilvegetable oil water corn syruphoney

Density and Atomic Mass

A Sulfur atom has about 32 times the mass of a Hydrogen atom. This means that a piece of Sulfur would be denser than Hydrogen unless the Hydrogen was greatly compressed.

Atoms that have higher atomic numbers have greater mass. Materials with atoms of higher

atomic mass can have fewer atoms for a given volume, but still have greater density.

The structure of the molecule affects density. Molecules may have structures that force atoms further apart leading to lower density.

Liquid Water Solid Water (Ice)

To find the density of an object1- Find the mass of the object

2- Find the volume of the object

3- Divide

Density = Mass

Volume

Units for density g/cm3 or g/ml

M = mass V= volume D = density

M = D x V V = M / D D = M / V

How do you find mass?

ScaleBalance with known weights Mass v. Weight

Mass is a property that does not change whereas weight depends on the pull of gravity.

On earth, we generally use weight as a measure of mass but that only works at this gravity.

How do you find volume?

Regular ShapesRuler

Irregular Shapes/liquidsGraduated cylinder

What about our density column?If we used the same volume

of each liquid, which would weigh the most?

If we weighed out the same mass of each liquid, which would have the most volume?

Water has a density of 1 g/mL. Which liquids would have a density of more than 1 g/mL?

rubbing alcohol

baby oil

vegetable oil

water

corn syrup

honey

Please complete the rest of the sheet. Feel free to work cooperatively and ask for help if you need it

Calculating density, mass and volume

Using the density triangle:

Cover up what you want to find and what’s left is the formula!D= M/VM=D X VV=M/D

Remember units must be g/ml or g/cm3 for density, ml or cm3 for volume and g for mass. Conversions/calculations may be necessary!

Density Calculation252 mL of a solution with a mass of 500 gAre the units right?

yesWhat am I looking for and what is the formula?

Density, D=M/VD = 500 g/ 252 mL = 1.98 Units? g/mL

1.98 g/mL

Mass CalculationsA solid with a density of 2.65 g/mL and

dimensions of 2.5 cm x 2.5 cm x 2.5 cmAre the units right?

No, need to calculate volume2.5*2.5*2.5 =15.625 cm3

What am I looking for and what is the formula?Mass, M=D*VM = 2.65 * 15.625 = 41.4 Units? 41.4 g

41.4 g

Volume CalculationsA 3.400 kg solid with a density of 10.74 g/mLAre the units right?

No, need to convert mass3.400 kg = 3400 g

What am I looking for and what is the formula?Volume, V=M/DV = 3400/10.74 = 316.57Units? mL

316.6 mL

Mixed Practice50.0 mg of a gas which occupies a volume of 0.0064 L

7.8 x 10-3 g/mL or 0.0078 g/ml26.5 g of a solution with a density of 7.48 g/mL

3.54 mLA 6.75 g solid with a volume of 5.35 cm3

1.26 g/mL

A solid with a volume of 1.68 cm3 and a density of 9.2 g/mL15.46g

An 80 mL aliquot of a solution with a density of 5.80 g/cm3  464 g