LEC MOD 3 Flashcards
A written statement that uses chemical symbols and chemical formulas instead of words to describe the changes that occur in a chemical rxn
Chemiical Equation
starting material in a chem reaction that undergoes change
Reactants
what does the meaning of arrow in a chem equation?
to produce
substance produce as a result of chem rxn
products
what does the plus sign mean in a chem equation?
reacts with and with
monoatomic
He,Ne,Ar,Kr,Xe
Diatomic
H2, O2, N2, F2, Cl2, Br2, I2
Tetraatomic
P4, As4
when elements ends with suffixes -ggen and -ine, what are their classification?
Diatomic
equation that has the same number of atoms on each element involved in the reaction on each side of the equation
Balanced Chemical equation
law of conservation of mass
atoms are neither created nor destroyed
process in which at least one new substance is produced as a result of chemical change
Chemical reactions
evidences of chemical change
color change
precipitate
gas and heat
odor change
Synthesis reaction; single product is produced from two or more reactants
Combination; A + B=AB
single compound breaks into 2 or more simpler substance
Decomposition; AB= A+B
AKA single displacement rxn; atom or molecules replaces an atom from a compound
Single replacement rxn;A+BC=Ac+B
two substances exchange parts with one another and form two different substancess
Double replacement; AB+CD=AD+CB
occurs when two ionic compounds are dissolved in h2o and form new ionic compound that does not dissolve
precipitation
“acid-base reaction”; an aquaeous acid-base rxn generally produces water and salt
Neutralization
reaction between substance and O2 that evolves to heat and light
CH+O2=CO2+H2O+fire
determination of the dimensionss,capacity, quantity or extent of something
Measurement
a measure of the total quantity of matter in an object
Mass
basic unit of mass in metric system
Gram (g)
a measure of the amount of space
Volume
basic unit of volume in MS
Liter (l)
a measure that determines the distance between two points
Lenght
basic unit of length in MS
Meter (m)
digits in a measurement that are kinown with certainty plus one digit that is estimated
Significant figures (sig figs)
process of deleting unwanted digits from calculated numbers
Rounding off
numerical system in which numbers are expressed in the form: A x 10^n
Scientifi Notation
the sum of the atomic masses of all the atoms represented in the chemical formula of a substance
Formula mass
a unit of measurement for the amount of substance
MOLE
Avogadro’s number value
1 mole =6.02 x 10^23 objjects
Founder of avogadro’s no.
Lorenzo Amadeo Avogadro
mass in grams of one mole of any pure substance
Molar mass (g/mol)
a homogenous mixture of two or more substances with each substance with each substance retaining its own chem identity
Solution
general properties of a solution:
contains a solvent and solute
has a variable compossition
properties change as the ratio of solvent ans solutw change
dissolved solutess are individual particles
solute uniformly distributed
solute can be separated by physical means such as evaporation
contains less than the maximum amount of solute that can be dissolved under the conditions of which the solution exists; solute is greater than solvent
Unsaturated solution
contains the maximum amount of solute that can be dissolved under the conditions of which the solution exists; excess solute
Saturated
solution is unstable wherein it temporarily contains more dissolved solute than the present in a saturated solution; formation of crystals; more excess solute
Supersaturated solution
solution containss a small solute; solute
Dilute solution
contains large amount of solute; Solute>solvent
Concentrated solution
solution wherein water is solvent; water=solvent
Aqueous solution
substance other than water is the solvent
Non-Aqueous solution
maxmum amount of solute that will dissolve in a given amount of solvent under a given set of conditions; like dissolves like
Solubilty
the number of moles of that species that is contained in 1 liter of the solution
Molarity mol/L
formula: Moles of solite/ liters of solution
the process in which more solvent is added to a solution in order to lower the concentration
Dilution
formula: C1 V1= C2V2
