2EXAM-HChem Flashcards
___ properties depend on the amount
___ properties depend on type of matter, not the amount
Extensive
Intensive
Chemical changes (are/are not) reversible
Are not
Changes of state are (physical/chemical)
What does this include
Physical
Boiling, melting
Elements are organized in the periodic table by ___ periods and ___ groups
7, 18
What is evidence of a chemical reaction
Production of heat or light, a color change, the production of a gas, or the formation of a precipitate
____________ describes that mass is conserved during chemical or physical changes. Mass of reactants=Mass of products
Conservation of mass
In scientific notation, the base must be…
Equal to or greater than 1 and less than 10
What is Avogadro’s number
6.022 x 10^23
What is the difference between accuracy and precision
Accuracy: describes how a measurement agrees with the correct or accepted value (bullseye)
Precision: describes how a measurement agrees with other values (consistency)
Sig figs contain all of the numbers known for certain plus
One estimate
What is the SI unit for: Mass- Length- Time- Amount of substance- Temperature-
Kilogram Meter Second Mole Kelvin
How do you convert C to F
How do you convert F to C
F=C*9/5 +32
C=(F-32)*5/9
Where are protons and neutrons located
The nucleus
The number of neutrons =
Mass number-number of protons
What are the four orbital shapes that electrons can occupy
S(sphere), p (peanut), d (double peanut), f (flowers)
What is the trend for atomic radius?
What is the trend for ionization energy?
Increases left and down
Increases right and up
What is ionization energy
The amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation
Electrons want to be unpaired until they’re forced to pair
Hund’s Rule
When assigning orbitals to electrons, always fill lowest energy first
Aufbau’s Principle
What are the rules for electron dot notation
No side can have more than two dots because each orbital can only hold two electrons
Each side gets one dot before doubling up
What is a photon
A package of energy that travels on transverse waves
The wavelength is between two ___
Crests
The amplitude of a wave is…
The distance from the middle to the top
Color of light is established by _____
Wavelength
_________ is how many waves pass a point in 1 second
Frequency
Frequency is represented by a __
V
What are units for frequency
Wps, cps, hertz, s^-1
_____ travel at the speed of light
Electrons
electrons start in (lowest/highest) possible energy
Lowest (ground state)
Increasing wavelength ____ energy
Decreases
Ionic bonding involves the ____ of electrons
Transfer
What are the two types of covalent bonding
Polar and nonpolar
What is electronegativity
A measure of the tendency of an atom to attract a bonding pair of electrons
How do you calculate N,A,S numbers for atoms/polyatomic ions
N is needed (they all need 8 expect H needs 2, Be needs 4, Boron needs 6)
A is available, use valence electron number and look at charge
S is N-A. Divide by 2 and put that number of lone pairs on the central atom
What are the two conditions that will result in a molecule being polar
One or more lone pairs on center atom (dipoles will angle)
If you have different atoms connected to your center (different electronegativities)
_____ are neutral
_____ have a charge
Atoms
Ions
All elements want to have the electron arrangement of the ______ noble gas
Nearest
D-block metals form ___
Cations
Oxyacids contain __,__, and a third element
H, O
When you’re naming compounds, use the full name of __ and __
Sulfur, phosphorus
How do you do empirical formula
Divide percentage by atomic mass, divide all solutions by smallest number, get whole numbers by multiplying ALL RESULTS
How do you find the molecular formula
Divide the total mass by the mass present in the compound
Use that as the subscript
Empirical formula is _____
Molecular formula is ____
Simplest
Actual
What are the 5 types of equations
Synthesis Decomposition Single Displacement Double displacement Combustion
Which is NOT a sign that a double replacement reaction will occur
Light is emitted, ppt is produced, H20 is formed, gas is formed
Light is emitted
The reaction Li+02—>Li20 is …
Synthesis and Combustion
When you add an acid to a base, the solution ______________
If you add a base to an acid, it ______
Stays pink
Flashes pink
How do you find the limiting reactant
Convert grams of the reactant to grams of the product
Whichever is less is the limiting
What must be the units for gas laws
Pressure-atm
Volume- l
Temp- K
If you’re using the ideal gas law for a wet/dry gas, make sure you have the correct ____ by using Dalton’s law
Pressure (subtract or add given water vapor pressure
The acid ____ the proton while the base _____ it
Donates/accepts
The conjugate base goes with the _______
Acid
What are the rules for naming acids and bases
Normal: ic \+1: per_ic -1: _ous -2:hypo_ous (Look at subscript)
When writing rate laws, don’t forget the _
K
What is the unit for k
M^-overall order -1 s^-1
The rate determining step is the ___ step
Slowest
LeChatelier’s Principle says that
When you put a stress on a reaction, it will respond to relieve the stress
Also called the equilibrium law
Adding a catalyst to a reaction shifts the reaction…
NOT AT ALL
NO SHIFT
Decreasing the volume makes the reaction shift towards
The side with less moles
Decreasing volume=
Increasing pressure
What is entropy
Measures the degree of disorder
All objects have a tendency to go towards _delta H and _delta S
-,+
Less energy, more disorder
Endothermic reactions ____ heat and the energy is in the ___
Exothermic reactions _____ heat and the energy is in the ____
Absorb, reactant
Release, product
What is enthalpy
Change in heat (delta H)
What is Hess’s Law of Intermediates
The heat of formation of the steps must add up to the total
What is Hess’s law of summation
Heat of reaction=sum of heat of formation of products times moles-sum of heat of formation of reactants times moles
Delta Hf values for elements are 0
Why
They are naturally occurring and no heat is absorbed
In Gibbs, temperature must be in _____
Kelvin
What element goes in the center for Lewis structure
Least electronegative
When doing Lewis structure, make sure..
Electrons drawn equals A number
Mr Cousineau serves ham sandwiches according to the following equation
1Ham+2Bread+1Cheese–>1Sandwich
If Mr. C buys 24 slices of bread, 14 slices of ham, and 16 slices of cheese, which ingredient will be the limiting reactant? (How do you know)
The bread
Divide each of the amount of ingredients you buy by the number of ingredients per one sandwich, whichever is the least (bread) is the limiting reactant
Nomenclature
Describe the rules for each situation
Binary ionic- cation unchanged and then the anion stem+ide
D-block ionic- cation unchanged, Roman numeral, anion stem+ide
Covalent- right of staircase cation, use prefixes di, tri, tetra, penta
Binary acid- hydro_____ic acid
Oxyacid- compare to polyatomic -ate form. Use per___ic, ___ic, ___ous, hypo___ous
If you need the mass of one molecule of something, what do you do
Convert molecules to moles and moles to grams
One mole is different from one _____
Molecule
How would you find the mass of one molecule of C8H18
Convert molecules to moles using Avogrado’s number and then convert moles to grams
Is wood heterogenous or homogenous
Heterogenous
Flammability is a ____ property
Chemical
Conductor of heat is a ___ property
Physical
Melting is a ___ property
Physical
Dissolving readily in water
Physical or chemical
Physical
Dissolving salt in water is a _____ change
Physical
Boiling is a ______ property
Physical
Density is an ___ property
Intensive
