Chemistry Block 2 Flashcards
Chemical Reactions Example
●matches (phosphorus and sulfur ignite with friction)
●cooking on gas (burning chemicals to produce energy)
●engines for vehicles (burning of chemicals produce energy) like cars, buses, planes etc.
●batteries (involves chemical reactions that produce electricity)
●antacid tablets/liquids (react with HCl in stomach to reduce stomach acid)
●toothpaste (sodium fluoride in toothpaste reacts to rebuild enamel and control bacteria)
●soap and shampoo (has sodium or potassium which clean dirt and oils off body)
AND MANY MORE……………..!!!
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4. Chemical Reactions
The number of formula units in a mole is known as _______.
Avogadro’s
What is Avogadro’s number?
6.02214199 x 10^23
Atomic mass (in grams) relationship with 1 mole.
atomic mass (in grams) of any atom will be the mass same as the mass of 1 mole of that particular atom/element.
A balanced chemical equation tells us about…
Reactants
–Products
–Their state
–Also Molar Ratios
Stoichiometry
“the study of mass relationships in chemical reactions”
Oxidation
the gain of oxygen and/or loss of hydrogen.
Reduction
the loss of oxygen and/or gain of hydrogen
Gas pressure
the force per unit area exerted against a surface.
–most commonly measured in millimeters of mercury (mm Hg), atmospheres (atm), and torr.
–SI unit is pascal
At sea level, the average pressure of the atmosphere is _______
760 mm Hg, that equals to 1 atm.
Pressure is measured using a _________
barometer
Boyle’s law
P- V relationship
Charles’s law:
T-V relationship
Gay- Lussac’s law:
P-T relationship
Combined gas law:
combination of these 3 gas laws
P1V1/T1=P2V2/T2
Explains relationship between mass of gas (M) and its volume (V)
“Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.”
PV = nRT
Where P = pressure of the gas (atm)
V = volume of the gas (L)
n = amount the gas in moles (mol)
T = temperature of the gas (K)
R = Ideal gas constant [a constant for all gases]
three types of intermolecular forces:
A. London dispersion forces
B. Dipole-dipole interactions
C. Hydrogen bonding
Although the three intermolecular forces are relatively weak compared to the strength of ionic and covalent bonds, they determine many properties of biomolecules such as_______.
melting point
boiling point
viscosity
3D shape
London Dispersion Forces
“Extremely weak attractive forces between atoms or molecules caused by electrostatic attraction between temporary induced dipoles.”
However, at any given instant, the electron density may be shifted more towards one part of the atom than another, thus creating a temporary dipole.
0.01 to 2 kcal/mol
Dipole-Dipole
“The attraction between positive end of dipole of one molecules and negative end of another dipole in the same or different molecule.”
Hydrogen Bonds
“A noncovalent force of attraction between the partial positive charge on a hydrogen bonded to an atom of high electronegativity, most commonly O or N, and the partial negative charge on a nearby O or N.”
Hydrogen bonding ranges from 2 to 10 kcal/mol.
Saturated solution:
that contains the maximum amount of a solute that can be dissolved at a given temperature.
Unsaturated solution:
that contains less than the maximum amount of a solute that can be dissolved at a given temperature.
Supersaturated solution:
that contains more than the maximum amount of a solute that can be dissolved at a given temperature under equilibrium condition.
It is not stable.
–when this solution is disturbed in any way, the excess solute precipitates- solution returns to equilibrium, and becomes merely saturated.
Factors Affecting Solubility
Nature of the solvent and solute
Temperature
Pressure
Henry’s law
higher the pressure, greater the solubility of a gas in a liquid.
Concentration of solution:
amount of solute dissolved in a given quantity of solvent.
When we need quantitative values, we can express the concentration of solution in 3 different ways
–Percent Concentration
–Molarity & Dilution
–Parts per million (ppm)
Molarity:
moles of solute per liter of solution.
Colloid:
a solution in which the solute particle diameter is between 1nm and 1000 nm.
Tyndall effect:
a characteristic of colloids in which, light passing through the colloid, scatters.
Brownian motion:
the random motion of any colloidal particle suspended in solvent.
Add colloids chart
Add colloids chart
Colligative Properties
“Any property of a solution that depends on the number of solute particles, and not on the nature of the particles.”
Colligative properties are:
- Freezing-point depression
- Boiling-point elevation
- Osmotic pressure
- Dialysis
Freezing-Point Depression
“The decrease in the freezing point of a liquid caused by adding a solute”
Boiling point:
“temperature at which the vapor pressure of the substance equals atmospheric pressure.”
Semipermeable membrane:
a membrane with pores that are big enough to allow solvent molecules to pass through them, but not big enough to allow the passage of larger solute molecules.
Osmosis:
the movement of solvent particles through a semipermeable membrane from a region of lower solute concentration (higher solvent concentration) to a region of higher solute concentration (lower solvent concentration).
Movement of solvent particles from higher to lower_____________ concentration.
Solvent
Movement of solvent particles from lower to higher _____________ concentration.
solute
Osmotic pressure:
the pressure necessary to prevent osmosis.
–Solution of higher concentration has a higher osmotic pressure.
Osmolarity (osmol):
the molarity multiplied by the number of particles produced by each formula unit of solute.
Isotonic solutions:
solutions with the same osmolarity.
Isotonic solution:
a term used primarily in the health sciences to refer to a solution with the same osmolarity as blood plasma and red blood cells.
• Use of isotonic IV fluids
Hypotonic solution:
a solution with lower osmolarity than blood plasma.
Hemolysis:
RBC in hypotonic solution, swell and finally burst.
Hypertonic solution:
a solution with higher osmolarity than blood plasma.
Crenation:
RBC, in a hypertonic solution, undergo shrinkage and acquire a notched surface.
Hemodialysis: .
A procedure for removing metabolic waste products or toxic substances from the bloodstream by dialysis