General Chemistry 2 Flashcards
What do solutions contain?
Solute and solvent
What is crystallization?
Dissolved solute comes out of a solution and forms crystals
How you increase solubility of solids, liquids and gases?
Solubility of liquids and gases increase with increasing temperature usually. Solubility of gases increase with decreasing temperature and increasing pressures
What is percent composition?
Mass of solute/ mass of solution x 100%
What is mole fraction?
X moles of B/ sum of moles of all components
What is molarity?
Number of moles of solute/ liter of solution
What is molality?
Number of moles of solute/ kilogram of solvent
What is Normality?
N = molarity x equivalents/ mol
What is the equation for dilutions?
C1V1= C2V2
What is an electrolyte?
Solutes that make conductive solutions
What makes a strong electrolyte and what are examples of strong and weak electrolytes?
A solute is considered a strong electrolyte if it dissociates completely into its ions.
Strong electrolytes: NaCl, KI, HCl
Weak electrolytes: Acetic acid, ammonia, weak acids and bases, HgCl2
What are non electrolytes and what types of molecules fall under this category?
Don’t ionize at all in aqueous solution, retain their molecular structure in solution, e.g. non polar gases and organic compounds (oxygen and sugar)
What are the 4 basic reaction types?
Combination reactions, decomposition reactions, single displacement reactions, double displacement reactions
What happens during oxidation reduction reactions?
Transfer of electrons, oxidation (loss of electrons) and reduction (gains electrons)
What happens to oxidizing and reducing agents?
- Oxidizing agent causes atom to undergo oxidation and itself is reduced
- Reducing agent causes other atoms to be reduced and is itself oxidized
How do you balance redox reactions?
Have to balance Net charge and number of atoms!
Steps:
1) separate 2 half reactions
2) balance the atoms of each half reaction, add H2O or H+ to balance h and O
3) Balance the electrons of each half reaction
4) Combine the half reactions
5) confirm the mass and charge are balanced
6) for basic reactions add OH- to neutralize the H+
What cells do spontaneous and non-spontaneous reactions occur in?
Spontaneous reactions occur in galvanic cells and non-spontaneous reactions in electrolytic cells
Does oxidation/reduction occur at the anode or the cathode?
Oxidation occurs at the anode
Reduction occurs at the cathode
What is the structure of a galvanic cell?
- Supply energy and used to do work
- Oxidation and reduction half reactions in separate containers called half cells connected by a wire or conductor
- Usually salt bridge used
What is the structure of the electrolytic cells?
- Oxidation and reduction half reactions placed in same container (no salt bridge required)
- Usually have battery or power source to drive the non spontaneous redox reaction
Concerning anodes and cathodes: which direction do electrons flow?
Electrons always flow from ANODE to CATHODE
What is the anode of an electrolytic and galvanic cell considered?
Anode of electrolytic cells is considered positive but anode of galvanic cell is considered negative
What is the equation for number of moles of electron transferred by an electrochemical cell?
i x t = n x F
Where i is current, n is number of moles of electrons, t is time in seconds, and F is faradays constant 96487 C (or J/V)
What is the reduction potential?
Tendency of a species to acquire electrons and be reduced, more positive value is the greater the tendency to be reduced, measured in volts
What is electromotive force (emf or E0Cell)? And what is the equation for it?
- Difference in potential between 2 half cells
- E0Cell = EoRed + EoOx
- EoCell of galvanic cell is positive and electrolytic cell is negative
BUNCH OF CELL EQUATIONS
PAGE 8 of notes
What is viscosity?
A measure of a fluids resistance to flow
What is miscibility?
The degree to which 2 liquids can mix
What is emulsion
Homogenous mix of 2 immiscible liquids
What are the properties of ionic solids?
High MP and BP, poor electric conductivity in solid phase
What is the equation for Q normally and during a phase change?
Q= Mc DeltaT
During phase change: Q= m Hl (latent heat of transformation of the substance)
What is evaporation/vaporization?
Molecules leave liquid phase and escape into the gaseous state, temperature of remaining liquid decreases (cooling process)
What is condensation?
Gas back to liquid phase
What is vapor pressure? And what is boiling point?
Vapor pressure: Pressure that the gas exerts over a liquid, increases as temperature increases
Boiling Point: Temperature at which the vapor pressure of the liquid equals the external pressure
What is melting/fusion and what is solidification/ crystallization/ freezing?
From solid to liquid and then from liquid to solid
What is sublimation and what is deposition?
Sublimation is solid to gas and deposition is gas to solid
Where can you find solid, liquid and gas phases on a phase diagram?
Typically gas phase found at high temp and low pressure
Typically liquid phase found at high temp and high pressure
Typically solid phase found at low temp and high pressure
What is the triple point of a phase diagram and what is the critical point of a phase diagram?
Triple point: Where all 3 phases are in equilibrium
Critical point: Temperature and pressure above which the liquid and gas phases are not possible and supercritical fluids exist instead
What is an Arrhenius acid and base?
Acid is a species that produces H+ in aqueous solution
Base is a species that products OH- in aqueous solution
What is Bronsted Lowry acid and base?
Acid is a species that donates protons
Base is a species that accepts protons
What is a Lewis acid and base?
Acid is electron pair acceptor
Base is electron pair donor
What is the value of Ka for strong acid?
Larger the Ka, stronger the acid
Strong bases have a high Kb
What is a neutralization reaction?
Acid + base -> water and salt
What is binding energy?
Amount of energy required to break up a given nucleus into its constituent protons and neutrons
What is radioactivity?
When nucleus is unstable and spontaneously emit particles or electromagnetic radiation
What is fusion?
When small nuclei combine into a larger nucleus, fusion reactions can only take place at extreme high temperature and pressure (thermonuclear reactions)
What is fission?
Large, heavy atom splits to form smaller more stable nuclei, release of large amount of energy, spontaneous fission rarely occurs
What is an alpha particle?
Emission of 4(He)2
What is beta decay?
Emission of a B particle which could be either electron (B-) or proton (B+)
B- decay means neutron is consumed and proton takes its place (Z increases by 1)
B+ decay means a proton is consumed and a neutron takes its place (z decreases by 1)
What is gamma decay?
Emission of a gamma particle which are high energy photons, A and Z remain same, lower energy of nucleus
What is electron capture?
Rare Process, Z decreases by 1, 0(e-)-1
