AP CHEMISTRY. Review SI system -know prefixes in blue on pg 10 Mass vs weight-an object’s mass...

AP CHEMISTRY

Chapter 1Chemical Foundations

Review

Review•SI system -know prefixes in blue on pg 10

•Mass vs weight-an object’s mass reflects the amount of matter it contains. An object’s weight is the pull of gravity on that matter.

UncertaintyMeasurements should include all certain digits

plus the first uncertain digit.Ex. Reading thermometer, buret, balance, etc.(On digital devices, the last digit shown is

uncertain)So what is the reading from this graduated cylinder? How many decimals are acceptable here?

The reading should be 52.8 ml where the 8 is the estimated digit.

You should be able to use and read these pieces of equipment.

Accuracy and

PrecisionWhich is which??

How Many Significant figures? 4.0023 4.00 0.04003 0.04 0.040

Sig. Figs in Calculations: A Review •significant figures in calculations• When multiplying or dividing, use the smallest total

number of sig. figs.• When adding and subtracting, use the smallest number of

decimal places.

Ex. 3.0×6.00 = 18 3.0 + 6.00 = 9.0•exact numbers-have infinite sig. figs.

Use of decimal point or scientific notation to show limit of significant figures. Ex. 600. or 6.00×102

Dimensional analysis- This should be a review of Chemistry I -conversions are found in

Appendix 6, pg. A26

In AP Chemistry, we will only use Celsius and Kelvin temperature units

0°C = 273.15K

Review: Density = Mass/Volume Units are g/cm3 for solids or

liquids and g/L for gases. The density of a substance is a

physical property of the substance and can be used to identify it.

This may look like a middle school review, but do you really understand it all? Make sure that you do!

Classification of Matter

Physical, Chemical, and Ambiguous ChangesIn a physical change, the chemical formula

does not change. All phase changes are physical changes.

In a chemical change, one or more new substances are formed.

Sometimes the determination as to whether a change is physical or chemical is not so simple and the change is termed “ambiguous”. An example could be an ionic compound dissolving in water. Weak chemical bonds form between the water molecules and the dissolved ions.

When a calcium ion dissolves in water, what type of change has occurred?

Separation of Mixtures

-distillation-chromatography-filtration

Gravity Filtration Vacuum Filtration

Types of Filtration used in AP Chemistry

ChromatographyChromatography is a procedure that

separates a mixture into its component parts based on the components attraction for the mobile and stationary phases. The distance that the component travels is compared to the distance that the mobile (solvent) phase travels on the stationary phase.

Types of chromatography:PaperGasThin-layer Liquid

Paper Chromatography