exam 2 Flashcards
What is stoichiometry
The numerical relationships between chemical amounts in a balanced equation
What is the limiting reactant?
The reactant that limits the amount of product in a chemical reaction
What is the theoretical yield?
The maximum amount of product that can be made in a chemical reaction based on the amount of limiting reactant
What is the actual yield?
The amount of product actually produced by a chemical reaction
What is the percent yield?
The percentage of the theoretical tield that is obtained, is calculated as the ratio of the actual yield to the theoretical yield (Actual/Theo)x100=%
Solve for the excess (find a random example
did you get it right lmfao
moles of limiting reactant–> molar ratio of limiting and excess-> grams of excess -> (total amt of excess-amount used)= excess leftover
What is a solution
A homogeneous mixture between two substances
What is the solvent?
The majority component of the mixture
What is the solute
The minority component of the mixture
What is an aqueous solution?
One in which water acts as the solvent
What is a dilute solution
A solution that contains a small amount of solute relative to the solvent
What is a concentrated solution
A solution thar contains a large amount of solute relative to the solvent
What is Molarity
A common way to express solution concentration
M=amount of solute (in moles)/volume of solution (L of solution)
What is the equation to find out how much stock solution to use in certain concentrations?
M1V1=M2V2
What are electrolytes
The dissolved ions in electrolyte solutions act as charge carriers that allow the solution to conduct electricity
What is a strong electrolyte
Substances that completely dissociate into ions when they dissolve in water and result in solutions that are strong electrolyte solutions
ex. Soluble Ionic compounds
what are nonelectrolytes/ weak electrolytes
Compounds that do not (completely) dissociate into ions when dissolved in water are nonelectrolytes
ex. Covalent Compounds, Organic Compounds
What is a strong acid
An acid that completely ionizes in a solution
What is a weak acid?
An acid that does not completely ionize in water: this is represented by half arrows in the formula
What are weak electrolytes?
weak acids are weak electrolytes and only weakly conduct electricity
What does it mean when a compound is soluble or insoluble
if the compound dissolves in water it is soluble, if it does not, it is insoluble
Review the solubility rules
What is a precipitation reaction?
Reactions in which a solid or precipitate forms when we mix two solutions: only insoluble compounds form precipitates
What is the difference between molecular, complete ionic, and net ionic equations?
A molecular equation is an equation that shows the complete neutral formulas for each compound in the reaction as if they existed as molecules.
A complete ionic equations show all of the ions present as either reactants or products, strong electrolytes are represented as their constituent ions but weak electrolytes are not
Net ionic equations only show the species that actually change during the reaction
What is an acid base reaction
A reaction where an acid reacts with a base and the two neutralize each other, producing water and an ionic compound (a salt)
What is a gas-evolution reaction?
a gas forms
What are the Arrhenius definitions of Acids and Bases
Acids are substances that produce H+ ions in an aqueous solution
Bases are substances that produce OH- ions in an aqueous solution
What are some strong acids?
HCI, HBr, HI, HClO4, HNO3, H2SO4 (only the first H+ lost is strong)
What are some common weak acids?
Formic acid (HCHO2), Acetic Acid (HC2H3O2), Hydrofluoric acid (HF)
What are some strong bases
LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Ca(OH)2, group 1 metals, Mg(OH)2, Sr(OH)2, Ba(OH)2, group 2 metals
What are some weak bases?
Ammonia NH3
What is a titration?
A titration is when a compound of a known concentration (known as the titrant) is reacted with a compound of unknown concentration but known volume (the analyte). The titrant is added to the analyte until the moles of titrant=the moles of analyte (this is the equivalence point. It is visualized by a color change)
What is the equivalence point in a titration?
the point in the titration when the number of moles of OH- added equals the number of moles of H+ initially in the solution
What are the reactants that under-go intermediate stages of gas evolution
Sulfides–>H2S
Carbonates and bicarbonates: (CO3^2-, HCO3)–> intermediate: H2CO3—> H20(l) + CO2(g)
Sulfites and bisulfites: (SO3^2-, HSO3)–> Intermediate: H2SO3—> H20 (l) +SO2
Ammonium: (NH4)–> Intermediate: (NH4OH)–> H20 (l) +NH3 (g)
What are redox reactions?
Reactions in which electrons transfer from one reactant to the other. Many of these involve reactions with oxygen, nonmetals and metals, and with nonmetals
What is oxidation?
The loss of electrons
What is reduction?
The gain of electrons
What is the oxidation state?
A number given to each atom based on the electron assignments, it is the “chatge” ot would have if all shared electrons were assigned to an atom with the greatest attraction for those electrons
What are the rules for Oxidation states? (in order)
- The oxidation state of an atom in a free element is 0
ex. Cu (ox=0), Cl2 (ox=0) - The oxidation state of a monoatomic ion is equal to its charge
ex. Ca2+ (ox=+2) Cl-(ox=-1) - The sum of the oxidation states of all atoms in:
- A neutral molecule or formula unit is 0
ex. H20 (2x(ox of H) +1x(ox of O)= 0 - An ion is equal to the charge of an ion
ex. NO3- (1x(ox of N)+ 3x(ox O)= -3
- A neutral molecule or formula unit is 0
- In their compounds metals have positive oxidation states
- Group 1A is always +1
-Group 2A is alwaus +2 - The oxidation states of nonmetals are assigned due to the table
What is the oxidation state of Fluorine
-1
What is the oxidation state of Hydrogen
+1
What is the oxidation state of Oxygen
-2
What is the oxidation state F
-1
What is oxidation in terms of a redox reaction?
Increase in oxidation state
What is reduction in terms of a redox reaction?
Decrease in oxidation state
What is an oxidizing agent and what is the reducing agent?
The oxidizing agent is the substance that causes the oxidation of another substance (it is always reduced)
The reducing agent causes the reduction in another substances ( it is always oxidized)
What is the standard state of H2?
gas
What is the standard state of N2?
gas
What is the standard state of O2?
gas
What is the standard state of F2?
gas
What is the standard state of Cl2?
gas
What is the standard state of CO?
gas
What is the standard state of CO2?
gas
What is the standard state of NO?
gas
What is the standard state of noble gases
gas
what is the standard state of H20
liquid
What is the standard state of Br2
liquid
What is the standard state of Hg
liquid
What is the standard state of (Hg2)
liquid
What is the standard state of I2
solid
What is the standard state of metalloids
solid
What is the standard state of other non-metals
solid
Why is only the first H+ lost in H2SO4 a strong acid
When it becomes HSO4- and becomes H3O+ + SO4^2- it does not ionize completely in water
what is boyles law and what is the formula
Pressure and volume are inversely related, as one decreases the other increases
P(1)V(1)=P(2)V(2)
What is charles law and what is the formula
Volume and temperature are directly proportional, as one increases the other increases V(1)/T(1)=V(2)/T(2)
What is Gay-Lussac’s Law
Pressure and temperature are directly proportional
P(1)/T1)=P(2)/T(2)
What is Avogadro’s law
Moles and volume are directly proportional
V(1)/n(1)=V(2)/n(2)
What is the standard pressure? What is the molar volume under standard conditions?
0.987 atm, 22.7 L
what are the three postulates of kinetic molecular theory
the size of the particle is negligible (has no volume) even though they have mass.
the average kinetic energy of a particle is proportional to T (in K)
Collisions between particles or container walls are perfectly elastic (energy is transferred but not lost) (particles that collide do not exert any force on eachother
what is the formulas for Kinetic Energy
KE=1/2mv^2, avgKE= 3/2RT
how is molar mass expressed in root mean square
kg/L
what is the R constant in the root mean square equation
8.3145 J/molxK
what are the equations for density
d=mass/vol or d= PM/RT
what does the kinetic molecular theory state
particles of different masses have the same average kinetic energy at a given temp