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Mole
The mole is a unit of measurement for the amount of substance or chemical amount. quantity of small particles that can be dealt with on a macroscale mole = 6.022x10^ particles = Avagadro's number TERM 2
Formula Weight/Mass
DEFINITION 2 Nanoscale and Macroscale (tiny particles so small we cannot deal with them on an individual basis TERM 3
Molar Mass
DEFINITION 3 Molar mass, symbol M, is a physical property characteristic of a given substance (chemical element or chemical compound), namely its mass per amount of substance. mass or weight of 1 mole of a substance H2O mass of 1 molecule = 18 amu mass of 1 mole = 18 g MM H2O = 18g/mole TERM 4
Chemical Reaction Equations
DEFINITION 4 use chemical formulas and element symbols to represent a chemical reaction reactants --> products *must be balanced *the number of each kind of atom needs to be the same on both *sides of the equation-conservation of atomic species *balance by adjusting all coefficients *trial and error-start with most complex *in the end it should be in the lowest whole # ratio TERM 5
Composition of Compounds
DEFINITION 5 obtained from chemical formula (gives # and kind of element)(also need atomic weight) is a weight of mass %: in one mole of a compound each element contributes to the molar mass the weight or mass % = total mass/MM of compound x
Empirical Formula
In chemistry, the empirical formula of a chemical compound is the simplest whole number ratio of atoms of each element present in a compound. Need the Wt% to find empirical formula. H2O2 molecular formula for hydrogen peroxide HO is the empirical formula H2O true molecular formula for water also the empirical formula TERM 7
Molecular Formula
DEFINITION 7 true/actual formula of a molecule [covalently bonded] compound how do we know if the empirical formula is the molecular formula-we usually need the molar mass TERM 8
Empirical Formula Reaction Data
DEFINITION 8 measure the reactants consumed and then get % composition combustion analysis involves burning organic cmp'd containing only C,H and O because of conservation of atomic species all the carbon ends up as CO2 and all the hydrogen ends up as H2O TERM 9
Stoichometry
DEFINITION 9 quantitative relationships that exist between the reactants and products in chemical reactions (via the balance equation) a stoichiometric amount of reactants refers to the exact mole ratio of reactants to each other TERM 10
Limiting Reagent
DEFINITION 10 the substance which is totally consumed when the chemical reaction is complete. limits the max amount of product procedure to evaluate the limit. reag. 1. calculate the amounts of product you can get first from one reactant and then from the other reactant 2. which ever reactant produces the least product is the limiting reagent 3. the other reactant is in XS and therefor is NOT completely used up
Combustion
the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. X+Z --> XZ most often between O or Halogens + some other element do not need to be pattern reaction TERM 17
Decombustion
DEFINITION 17 XZ ---> X+Z reverse combustion stable compound need a continuous source of energy - heat unstable combustion require only some initiating TERM 18
single displacement
DEFINITION 18 also called single-replacement reaction, is a type of oxidation-reduction chemical reaction when an element or ion moves out of one compound and into another. A+XZ---
AZ+X one element sets another element free TERM 19
exchange/double displacement
DEFINITION 19 AD+XZ--->AZ+XD exchange reactions most involve ions in (aq) solution. requires 2 different + and 2 diff - ions reaction occurs when ions are removed from solution -form a molecular compound: acid/base neutral ion -forms a solid (insoluble product): precipitation reactions -forms a gas TERM 20
Precipitation reactions
DEFINITION 20 Precipitation is the formation of a solid in a solution or inside another [exchange reactions: AD+XZ-->XD to have a prec. reaction ether AZ or XD or both need to be insoluble otherwise you just have "ion soup"
Ionic and New Ionic Reactions
not all mixtures of ions react even in reactive ionic solutions not all ions react (spectator ions) a complete ionic reaction shows all ions, reactive and spectator Net ionic equation shows only reactive ions and products TERM 22
Heat
DEFINITION 22 all chemical reactions occur with the release of absorption of energy reactions that release energy are called exothermic heat (thermal energy), light, sound (acoustic), electrical, mechanical reactions that absorb energy are called endothermic TERM 23
Oxidation/Reduction reactions REDOX
REACTIONS
DEFINITION 23 Redox (shorthand for REDuction-OXidation) reactions describe all chemical reactions in which atoms have their oxidation number (oxidation state) changed. involve actual or partial transfer or e-'s oxidation-loss of e-'s reduction-gain of e-'s TERM 24
Identification of redox reactions
DEFINITION 24 involve the change of oxidation states for at least two chemical elements for monotomic ions-charge # = oxidation (#) state 1st step assign oxidation states TERM 25
Non ionic reactions (typically) involving non-
metals
DEFINITION 25 in a covalent bond the bonding electrons are not shared equally between the bonded atoms unless they are the same if the bonded atoms are different the shared electrons are partially transferred to the element with the highest electronegativity the element in the bond with the higher EN is assigned all of the shared e-'s as if it were ionic--> negative OS the element with the lowest EN loses shared e-'s as if it were ioic and is assigned positive OS
Molarity
the distribution or e-'s in a molecule can be uniform or nonuniform uniform-molar is not polar nonuniform-molar is polar, electrons are not evenly distributed (think of chocolate chip cookie) TERM 32
Factors affecting solubility
DEFINITION 32 polarity of solute vs solvent "like dissolves like" polar solvents (like water) dissolve polar cmp'ds and ionic cmp'ds non polar solvents dissolve non polar cmp'ds temperature-most solids the solubility goes up as the temp goes up, for gasses solubility down as temp up, pressure has little effect on solubility on solids and liquids, for gasses solubility up as P up TERM 33
Concentration units
DEFINITION 33 qualitative description- -solution is dilute, not much solute - concentrated, lots of solute quantitative descriptions -% concentration -molarity = m = solute/kg solvent -PPM/parts permillion-used for ultra low concentrations TERM 34
electrolytes
DEFINITION 34 soluble ionic cmpd's and some molecular cmp'ds fully ionize/dissociate in water ions solution conduct electricity: called electrolytes partially soluble ionic cmp'ds and some molecular cmp'ds only partly ionize/dissociate in (aq) solution TERM 35
Bronsted-Lowry definition
DEFINITION 35 Acid-donates protons to another substance Base-accepts protons from another substance
Arrhenious
Definition
Acid-substance that forms H+ in solution Base-substance that forms OH- in solution TERM 37
Strong Acids/Bases
DEFINITION 37 Fully ionized/dissociated in H2O TERM 38
Weak acid/bases
DEFINITION 38 partly ionized/dissociated in water H2O TERM 39
properties of acids and
bases
DEFINITION 39 taste -acid:tart, sour. weak acids are used in many foods - base:bitter, chalky. milk of magnesia strong acids and bases are corrosive poisons-destroy living tissue on contact acid/base neutralization-most important reaction of acid/bases
