08/24/22
● Need aleks thingy for next wednesday.
● 7 base units
○ Length = Meter = m
○ Mass = kilogram = kg
○ Time = second = s
○ Electrical current = ampere = A
○ Temperature = kelvin = K
○ Amount of substance = mole = mol
○ Luminous intensity = candela = cd
● Mass is a measure of the amount of matter in an object or sample
●
● There are two temp scales used in chemistry
○ The celsius scale (C
■ Freezing point (pure water) O degrees C
■ Boiling point (pure water) 100 degrees C
○ The kelvin scale (K)
■ The absolute scale
■ Lowest possible temp being 0 k (absolute zero)
○ K = C + 273.15
● Volume : length x width x height
○ Volume has units of length cubed (m^3, cm^3, mm^3..)
○ A practical unit for volume is the liter (L)
● Density: the ratio of mass to volume
○ D = m/v
, ■ D = density, m = mass, v= volume
○ Density has units of mass / volume
● Two types of numbers
○ Exact numbers
■ Defined values
■ 1 kg = 1000 g
■ Are determined by counting
■ 28 students in one class
○ Inexact numbers
■ Measured by and method other than counting
■ Length mass
08/26/22
● Chem Learning strategy
○ Take notes and do work every time you work on chem problems
● Significant figures
○ Any nonzero digit is significant
■ 112.1 4 significant figures
○ Zeros between nonzero digits are significant
■ 305 3 significant figures
■ 50.08 4 significant figures
○ Zeros to the left of the first nonzero digit are non significant
■ 0.0023 2 significant figures
■ 0.000001 1 significant figures
○ Zeros to the right of the last nonzero digit are significant if a decimal is present
■ 400.0 4 significant figures
○ Zeros to the right of the last nonzero digit in a number that does not contain a
decimal point may or may not be significant
■ 400 1, 2, or 3 - ambiguous
○ To avoid ambiguity, use scientific notation to express S.F.
■ 4 x 10^2 1 S.F
■ 4.0 x 10^2 2 S.F
■ 4.00 x 10^2 3 S.F
● Calculations & S.F.
○ Addition and subtraction
■ The answer cant have more digits to the right of the decimal point than
any of the original to the number
○ Multiplication & division
■ The # of significant figures in the answer is limited to the number with the
smallest number of significant figures
■ Exact numbers have an infinite number of significant figures and do not
limit the number of significant figures in a result
, ○ Multiple steps
■ Round at the end of the calculation to reduce any rounding errors.
■ Do not round after each step
● Accuracy and Precision
○ How close repeated measurements are to each other: precision
○ How close the experimental measurements are to the real value: accuracy
08/29/22
● Conversions with squared/cubed units
○ Ex. 1 ft = 12 in, but 1 ft^2 is not 12 in^2
(1 ft)^2 = (12 in)^2
2 2
1 ft = 12^2 in^2
1 ft^2 = 144 in^2
● Ex. How many cm^3 = 1 m^3
1 m = 100 cm
(1 m)^3 = (100 cm)^3
1^3 m^3 = 100^3 cm^3
1 m^3 = 10^6 cm^3
● Density is a conversion factor
○ Ex. Olive oil density = 0.92 g / ml
Use density to write a conversion factor:
__ g olive oil = __ mL olive oil
0.92 g olive oil = 1 mL olive oil
A recipe calls for 75 mL olive oil
How could you measure that with a balance?
● Conversion factors: infinite variety:
○ Ex.
○ ___ wheels = ___ cars Maybe?
○ ___ miles = ___ hours on I-25 75 miles per hour?
○ ___ miles = ___ gallons of gas 32 miles per gallon?
○ How many hours will it take to drive 93 miles on I-25?
, ● Chemistry learning strategy
○ Visualize your world at the atomic level
● Matter has mass and occupies space
● Physical states of matter: particle view
○ Solid particles are held closely together in an ordered fashion
○ Liquid particles are close together but are not held rigidly in position
○ Gas particles have significant separation from each other and move freely
● Shape and volume
○ Solids do not conform to the shape of their container
○ Liquids do conform to the shape of their container
○ Gases assume both the shape and volume of their container
● The periodic table consists of about 100 elements. An atom is the smallest unit of an
element.
● A molecule has 2 or more atoms bonded together
○ A water molecule (H2O) contains 1 oxygen atom and 2 hydrogen atoms
○ A hydrogen molecule (H2) contains 2 hydrogen atoms
● Substances and Mixtures
○ Pure substance: 1 element or 1 compound
○ Element: only 1 type of atom
○ Compound : has 2 or more elements in fixed proportions
○ Mixture 2 or more substances in variable proportions
● Mixture: 2 or more substances in variable proportions
○ Homogeneous mixture : uniform
○ Heterogeneous mixture : non - uniform
08/31/22
● Phase changes
● Need aleks thingy for next wednesday.
● 7 base units
○ Length = Meter = m
○ Mass = kilogram = kg
○ Time = second = s
○ Electrical current = ampere = A
○ Temperature = kelvin = K
○ Amount of substance = mole = mol
○ Luminous intensity = candela = cd
● Mass is a measure of the amount of matter in an object or sample
●
● There are two temp scales used in chemistry
○ The celsius scale (C
■ Freezing point (pure water) O degrees C
■ Boiling point (pure water) 100 degrees C
○ The kelvin scale (K)
■ The absolute scale
■ Lowest possible temp being 0 k (absolute zero)
○ K = C + 273.15
● Volume : length x width x height
○ Volume has units of length cubed (m^3, cm^3, mm^3..)
○ A practical unit for volume is the liter (L)
● Density: the ratio of mass to volume
○ D = m/v
, ■ D = density, m = mass, v= volume
○ Density has units of mass / volume
● Two types of numbers
○ Exact numbers
■ Defined values
■ 1 kg = 1000 g
■ Are determined by counting
■ 28 students in one class
○ Inexact numbers
■ Measured by and method other than counting
■ Length mass
08/26/22
● Chem Learning strategy
○ Take notes and do work every time you work on chem problems
● Significant figures
○ Any nonzero digit is significant
■ 112.1 4 significant figures
○ Zeros between nonzero digits are significant
■ 305 3 significant figures
■ 50.08 4 significant figures
○ Zeros to the left of the first nonzero digit are non significant
■ 0.0023 2 significant figures
■ 0.000001 1 significant figures
○ Zeros to the right of the last nonzero digit are significant if a decimal is present
■ 400.0 4 significant figures
○ Zeros to the right of the last nonzero digit in a number that does not contain a
decimal point may or may not be significant
■ 400 1, 2, or 3 - ambiguous
○ To avoid ambiguity, use scientific notation to express S.F.
■ 4 x 10^2 1 S.F
■ 4.0 x 10^2 2 S.F
■ 4.00 x 10^2 3 S.F
● Calculations & S.F.
○ Addition and subtraction
■ The answer cant have more digits to the right of the decimal point than
any of the original to the number
○ Multiplication & division
■ The # of significant figures in the answer is limited to the number with the
smallest number of significant figures
■ Exact numbers have an infinite number of significant figures and do not
limit the number of significant figures in a result
, ○ Multiple steps
■ Round at the end of the calculation to reduce any rounding errors.
■ Do not round after each step
● Accuracy and Precision
○ How close repeated measurements are to each other: precision
○ How close the experimental measurements are to the real value: accuracy
08/29/22
● Conversions with squared/cubed units
○ Ex. 1 ft = 12 in, but 1 ft^2 is not 12 in^2
(1 ft)^2 = (12 in)^2
2 2
1 ft = 12^2 in^2
1 ft^2 = 144 in^2
● Ex. How many cm^3 = 1 m^3
1 m = 100 cm
(1 m)^3 = (100 cm)^3
1^3 m^3 = 100^3 cm^3
1 m^3 = 10^6 cm^3
● Density is a conversion factor
○ Ex. Olive oil density = 0.92 g / ml
Use density to write a conversion factor:
__ g olive oil = __ mL olive oil
0.92 g olive oil = 1 mL olive oil
A recipe calls for 75 mL olive oil
How could you measure that with a balance?
● Conversion factors: infinite variety:
○ Ex.
○ ___ wheels = ___ cars Maybe?
○ ___ miles = ___ hours on I-25 75 miles per hour?
○ ___ miles = ___ gallons of gas 32 miles per gallon?
○ How many hours will it take to drive 93 miles on I-25?
, ● Chemistry learning strategy
○ Visualize your world at the atomic level
● Matter has mass and occupies space
● Physical states of matter: particle view
○ Solid particles are held closely together in an ordered fashion
○ Liquid particles are close together but are not held rigidly in position
○ Gas particles have significant separation from each other and move freely
● Shape and volume
○ Solids do not conform to the shape of their container
○ Liquids do conform to the shape of their container
○ Gases assume both the shape and volume of their container
● The periodic table consists of about 100 elements. An atom is the smallest unit of an
element.
● A molecule has 2 or more atoms bonded together
○ A water molecule (H2O) contains 1 oxygen atom and 2 hydrogen atoms
○ A hydrogen molecule (H2) contains 2 hydrogen atoms
● Substances and Mixtures
○ Pure substance: 1 element or 1 compound
○ Element: only 1 type of atom
○ Compound : has 2 or more elements in fixed proportions
○ Mixture 2 or more substances in variable proportions
● Mixture: 2 or more substances in variable proportions
○ Homogeneous mixture : uniform
○ Heterogeneous mixture : non - uniform
08/31/22
● Phase changes
