Unit 1: Essentials Flashcards
states of matter
Physical form of matter - solid, liquid or gas
Each phase has a distinct set of properties across a large number of compounds
Each phasee is different beause of the distance and interactions between their particles
dimensional analysis
A problem solving technique that allows us to convert measurements from one unit to another or from one quantity to another
base units of measurement
Unit Symbol__Quantity meter m length kilogram kg mass second s time Kelvin K temperature Celcius °C temperature mole mol amount of substance
chemical properties
How something will react
Defined by what chemical changes it can undergo; this will alter the composition of the material
EX:
- flamability
- resistance to rust
- stability in water
matter
Anything that occupies space and has mass
composition of matter (decision tree)
work
Capacity to move something
The action of a force over a distance
Chemistry
The study of matter and the transformations it can undergo
random error
Caused by the factors beyond your control and can go in either direction
particles
A small portion of matter
What does a chemist do?
study matter
includes studying structure, symbols, nomenclature, properties, reactivity, calculations and lab skills
Fahrenheit
Measurement of temperature; most common in America
Symbol: °F
Water boils: 212°F
Room temp: 77°F
Ice melts / water freezes: 32°F
TF = 1.8 TC + 32
qualitative
Descriptive information
scientific method
A method of inquiry or investigation that involves cycles of observation and interpretation
A set of guidelines for skeptically investigating the world; it is “a way of trying not to fool yourself”
physical change
An experimental tehnique that does not alter the particles involved
Separate a mixture into its pure substances
EX: Solid carbon dioxide (dry ice) sublimes to make carbon dioxide gas
mixture
Matter that contains 2 or more types of particles
Can be physically separated
semimetals
AKA metalloid
An element that has properties intermediate between those of metals and nonmetals
An element with physial properties resembling a metal but chemical reactivity like that of a nonmetal
chemical change
Reaction
A process in which one or more substances are converted into new substances that have compositions and properties different from those of the original substance
EX: Methane burns in air (combusts) to produce water and carbon dioxide
atom
A single particle
One of the fundamental units of matter
The smallest particle of an element that retains the characteristic chemical properties of the element
diluted
Adding water to a concentrated sample
McVc = MdVd
M: molarity
V: volume
c: concetrated solution
d: diluted solution
homogenous mixture
Contains more than 1 type of particle but it has uniform composition throughout
EX: Salt water - water molecules with salt distributed uniformly throughout the entire sample
Kelvin
Measurement of temperature; most common in science
Has an absolute 0 - 0K is the coldest possible temperature
Symbol: K
Water boils: 373.15K
Room temp: 298.15K
Ice melts/water freezes: 273.15K
TK = TC + 273.15
electrical potential energy
Energy of charged particles near each other
density
Ratio of the object’s mass to its volume, usually reported in units of g/mL
d = m / v
Water has a density near 1 g/mL at room temp
Gases are lower - approx 10-3 g/mL
Solids are higher - up to 20 g/mL
electrolysis reaction
chemical method
Electrolysis: A process in which a nonspontaneous oxidation-reduction reaction is forced to occur upon passage of electric current thru a sample
hypothesis
Tentative explanation of a natural phenomenon
Must satisfy 2 criteria:
- testable
- falsifiable
kinetic energy
Energy of motion
The energy possessed by an object because of its motion
solute
The compound being dissolved
The lesser amount
heterogeneous mixture
Contains more than 1 type of particle but is not uniform throughout
EX: oil & vinegar dressing - contains distinct regions and is not uniform throughout
When is a chemical system most stable?
When they have minimized their potential energy
Molecules form and reactions happen because they stablize the particles involved by minimizing their electrical potential energy
scientific theory
A set of many observations collected under many different circumstances that agree with each other and provide a cohesive explanation of the physical world
* not proven, just hasn’t been disproven *
potential energy
energy of position
systemic error
Often caused by using instruments incorrectly and tend to skew the data in one direction
nonmetals
An element that typically has a dull appearance and is a poor conductor of electricity
energy
Capacity to do work or transfer heat
atomic theory
The theory that all matter is made up of tiny indivisible particles (atoms).
Most important theory in Chemistry
What is the reactant of a chemical reaction?
Left side of a chemical equation
A substance converted into another substance(s) during a chemical reaction
falsifiable
A hypothesis has falsifiability if it can logially be proven false by contradicting it with a basic statement.
metals
An element characterized by luster and the ability to conduct electricity
chemical equation symbols
Reactant (left): original substances
Product (right): new substances
→ produces or yeilds
+ reacts with / added to
→ (w/ delta above) heat is a catalyst for the reaction
→ (w/ Fe above) iron is a catalyst
NR no reaction
(s) solid or precipate
(l) liquid
(g) gas
(aq) aqueous solution
dependent variable
The value that is measured
Plotted on y-axis (vertical)
What is the product of a chemical reaction?
Right side of a chemical equation
A substance formed from another substance(s) during a chemical reaction
aqueous solution
Homogeneous mixture between water and a soluble compound
Not technically a state of matter but is so common that it’s treated that way
Symbol: (aq)
pure substance
Matter that contains only 1 type of particle
Can’t be physically separated
chemical formula
Atomic composition of a compound
Communicates the elements involved using symbols from the periodic table and the relative numbers of those elements, using subscripts
Molecular or covalent compounds ⇒ molecular formula
Ionic compounds ⇒ formula units
Why is Chemistry called the central science?
It explains much of the world around us
Also bridges the gap between physics and biology
quantitative
Numeric information
precise
Measurements that agree with each other
Could all be right or wrong but they’re close to each other
element
A pure substance that cannot be broken down to a more fundamental substance by a chemical method
EX: Hydrogen (H) or Oxygen (O)
heat
Capacity to change something’s temperature
instrument
A tool with the capacity to compare physical quantities
compound
A substance composed of 2 or more elements combined in definite proportions
A pure substance that can be broken down further by a chemical method
EX: Water (H2O) contains a single type of particle but can be broken down to Hydrogen and Oxygen
molarity
The number of moles of solute per liter of solution
M = mol of solute / L solution
Units: mol/L or M (molar)
Symbol: M
scientific inquiry
Asking and answering questions about the world according to the rules of the scientific method
concentration
The relative amounts of solute and solvent in a solution
The amount of substance per amount of water (solvent) in an aqueous solution
molecule
A single particle made from 2 or more atoms
2 or more elements bound together in a discrete arrangement
scientific law
A statement about nature that is always observed under a set of specific conditions
Unlike a theory, it does not provide any explanation for its observations
EX: conservation of mass, conservation of energy
composition
What matter is made of - the number and type of particles it contains
mathematical and physical models
Representations of reality that allow us to predict behavior
Component of scientific theories
intensive
Does not depend on amount
Density is an important property of matter because it is intensive
Celsius
Measure of temperature; most common outside America
Symbol: °C
Water boils: 100°C
Room temp: 25°C
Ice melts / water freezes: 0°C
TC = (TF - 32)/1.8
physical properties
Describe what matter is like
Something that can be observed without altering the composition of the material
EX:
- color
- density
- conductivity
- mass
- volume
derived units
Multiplying or dividing measurements with base units produces a new quantity with derived units.
EX: Area (m2) or volume (m3)
1 mL = 1 cm3
moles
Concept introduced to make it more convenient to count atoms
1 mole of a substance contains 6.02 x 1023 particles (Avogadro’s Number)
Measure of the amount of a substance
experiment
A set of observations performed under controlled conditions that directly evaluate the merits of the hypothesis
accurate
Measurements that are close to the true or expected value
solvent
The substance doing the dissolving
The greater amount (e.g. water in an aqueous solution)
slope
Slope of the trendline represents the constant of proportionality for the 2 variables
rise / run
change in y / change in x
uncertainties in measurements
There is error associated with every piece of scientific data ever collected
No measurement is perfect
2 types of error:
- random error
- systemic error
independent variable
The value the experimenter controls
Plotted on x-axis (horizontal)
testable
The claims the hypothesis makes can be evaluated with experient
