International System Of Units (Metric System). Types of Measurements. 1- QUALITATIVE MEASUREMENTS: observations of reactions — changes in color and physical state. 2- QUANTITATIVE MEASUREMENTS : which involve numbers . Use SI units — based on the metric system.
1- QUALITATIVE MEASUREMENTS:observations of reactions — changes in color and physical state.
2- QUANTITATIVE MEASUREMENTS:which involve numbers.
# of spaces the decimal moves is the power of 10
If exponent is positive, move decimal to the right
If exponent is negative, move decimal to the left
4.285 x 102 428.5(move decimal 2 spots right)
4.285 x 10-4 0.0004285(decimal moves 4 spots left)
Converting From Scientific to Standard Notation
The SI unit of volume is the amount of space occupied by a cube that is 1 m along each edge. This volume is the cubic meter (m)3. A more convenient unit of volume for everyday use is the liter, a non-SI unit.
A liter (L) is the volume of a cube that is 10 centimeters (10 cm) along each edge (10 cm 10 cm 10 cm = 1000 cm3 = 1 L).
The volume of 20 drops of liquid from a medicine dropper is approximately 1 mL.
AluminumDENSITY - an important and useful physical property
Densityis the amount of matter in a given volume. Density can be expressed in grams per milliliter (g/mL) or grams per cubic centimeter (g/cm3).
PROBLEM: Mercury (Hg) has a density of 13.6 g/cm3. What is the mass of 95 mL of Hg?
Sp.Gr. =Density of substance (g/ml) / Density of water (g/ml)
If blood has a density of 1.05 g/mL, how many liters of blood are donated if 575 g of blood are given?
1) 0.548 L
2) 1.25 L
3) 1.83 L
The normal temperature of a chickadee is 105.8°F. What is that temperature in °C?
1) 73.8 °C
2) 58.8 °C
3) 41.0 °C
1 mol = Avogadro’s Number = 6.02 × 1023 units
1 mole C
1 mole H2O
1 mole NaCl
= 6.02 x 1023 C atom
= 6.02 x 1023H2O molecules
= 6.02 x 1023NaCl “molecules”
(technically, ionics are compounds not molecules so they are called formula units)
6.02 x 1023 Na+ ions and
6.02 x 1023Cl– ions
6.02 x 1023 particles
6.02 x 1023 particles
Note that a particle could be an atom OR a molecule!
1 mole of C atoms = 12.0 g
1 mole of Mg atoms = 24.3 g
1 mole of Cu atoms = 63.5 g
6.02 × 1023 particles = 1 mol = molar mass
g= g/mol x mol
1.27Converting between grams and moles
g = mol x g/mol
mol = g g/mol