Intro to Chemistry Flashcards
Matter
Anything that occupies space and has mass. (states = solid, liquid and gas)
Mass
The quantity of matter which a substance possesses and, depending on the gravitational force acting on it, has a unit of weight assigned to it.
Weight formula
w = mg
Inertia
property of mass to resist a chang eof position or motion
Density
D = m (g) / V (cm^3 or mL) grams/liter
distinct substance
substance that can be subdivided inot the smlalest particle that still has the properties of that substance
element
made up of only one atom
compound
multiple atoms joined together
Law of Definite composition (or Proportions)
compounds are made by combining atoms of two or more elements in a definite proportion or ratio by mass
Molecule
smallest naturally occurring unit of a compound
has a definite shape determined by how the atoms are bonded to or combined with each other
Mixtures
- Composition is indefinite (generally heterogeneous) ex. marble
- Properties of the constituents are retained
- Parts of the mixture react differently to changed conditions
Distinct Substances
Elements:
- Composition is made up of one kind of atom Ex. nitrogen, gold, neon
- All parts are the same throughout (homogeneous)
Compound:
- Composition is definite (homogeneous) Ex. water carbon dioxide
- All parts react the same
- Properties of the compound are distinct and different from the properties of the individual elements that are combined in its make-up
Heterogeneous
Of or denoting a process involving substances in different phases (solid, liquid, or gaseous) Ex. Granite, Wood, blood)
Homogeneous
similar or similar kind of nature Ex. air, sugar in water, stainless steel)
Physical Properties
Can usually be observed with our senses
Include everything about a substance that can be noted when no change is occurring in the type of structure that makes up its smallest component
Ex. physical state, color, odor, solubility in water, density, melting point, taste, boiling point, and hardness
Chemical properties
properties that can be observed in regard to whether or not a substance changes chemically, often as a result of reacting with other substances.
Ex. iron rusts in moist air, nitrogen does not burn, gold does not rust, sodium reacts with water, silver does not react with water, and water can be decomposed by an electric current.
Physical change
Alters some aspect of the physical properties of matter, but the composition remains constant.
Most altered are form and state
Ex. breaking glass, cutting wood, melting ice, and magnetizing a piece of metal, water changing its state
Chemical change
Changes in the composition and structure of a substance that are always accompanied by an energy change
Exothermic reaction
energy given off (heat or light or both)
endothermic reaction
absorb more energy
Activation energy
the energy necessary to get the reaction going by increasing the energy of the reactants so they can combine
Know how to read graphs
Law of conservation of Matter
The mass of the reactants equals the mass of the products.
Matter can neither be created nor destroyed, but only changed from one to another
Energy
the capacity to do work
done whenever a force is applied over a distance
Anything that can force matter to move to change speed, or to change direction has energy.
Charge = stored energy
Work
Measured in Joules
Kilocalaries: 4.18x10E3 joules (J) = 2 kilocalorie
Forms of Energy
Energy in reaction is evolved heat
Light, sounds, mechanical energy, electrical energy, and chemical energy
Potential energy = stored energy due to overcoming forces in nature
Kinetic energy = energy of motion
enthalpy
Delta H = H products - H reactants
Delta H > 0 = endothermic
Delta H
Law of Conservation of Energy
Energy is neither created nor destroyed in ordinary physical and chemical changes
Law of Conservation of Mass and Energy
Mass and Energy are interchangeable under special conditions
E = mc^2 E = Mass x (Velocity of light)^2
SI Base Units
mass - kilogram
length - meter
time - second
electric current - ampere
temperature - kelvin
amount of substance - mole
luminous intensity - candela (cd) - rarely used
Prefixes used with SI Units
hecto - h - 100 - 10^2
deka - da - 10 - 10^1
deci - d - 0.1 - 10^-1
centi - c - 0.01 - 10^-2
milli - m - 0.002 - 10^-3
micro - mu - 10^-6
nano - n - 10^-9
pico - p - 10^-12
10 mm = ? cm
1 cm
100 cm = ? m
1 meter
1,000 m = ? km
1 km
1,000 mL = ? L
1 L
1,000 cm^3 = ? L
1 L
1 mL = ? cm^3
1 cm^3
1,000 mg = ? g
1 g
1,000 g = ? kg
1 kg
Temperature Conversion Factors
K = C + 273
C = K - 273
Calorie
Raise 1 gram of water by 1 degree C
1 carolie = ? joules
4.18 joules
