1.5: Lab Skills, etc. (start: "Other Notation") Flashcards
aqeuous
is dissolved in water
mixture
composed of two or more different substances that can be separated by physical means
solution
a homogeneous mixture
aqueous solution
a solution where something is dissolved in water
NaCl(aq) means that (2 things)
sodium chloride is dissolved in water and is a homogeneous mixture.
alloy
a solution of two metals
brass is made from
copper and zinc
name the five ways to separate substances in a mixture
- gravitational and vacuum filtration
- distillation
- chromatography
- extraction (water and oil)
- Crystallization (salt out of water)
extraction
when two or more liquids have different polarities they will not mix and can be separated with a separatory funnel.
alloy (mixtures)
a mixture of two or more metals, heated before they can mix, and then cooled.
separation factors: chromatography:
density and polarity
separation using a mobile and stationary phase
separation factors: distillation:
boiling point
separation of 2 or more liquids
sep. factors: filtration
particle size
separation of a solid and a liquid
sep. factors: dissolving
solubility
sep. factors: crystalization
freezing point
If both parts of a solution are in the same phase, which is the solvent and solute?
solvent: greater mass(solid) greater volume (gas/liquid)
solute: lower mass (solid) lower volume (gas/liquid)
desalination:
separation of salts from water
Name at least five forms of energy:
light, electromagnetic, mechanical, solar, geothermal, nuclear, chemical, electrical, heat/thermal
what are the four forms of energy most used in chemistry?
nuclear, chemical, electrical, and thermal/heat
what two factors control the amount of kinetic energy in particles?
how fast the particles are moving and how many particles there are
thermal energy + formula
the total kinetic energy of all the combined particles.
KE = 1/2 mv^2 (m=mass, v=velocity)
Will different masses of the same substance have different thermal energies?
yes, thermal energy is dependent on mass.
SAMPLE SIZE MATTERS
is there a formula for potential energy?
no, it is not measurable
heat
the transfer of energy (usually thermal) from a body of high to low temperature
thermal energy is associated with the…
random movement of particles
q =
heat/energy
Law of Conservation of Energy
energy can neither be created nor destroyed
specific heat capacity (symbol and def.)
(c)J/g The rate at which heat will be absorbed.
formula to calculate quantity of heat absorbed
q = mc(delta-T)
temperature
measure of average kinetic energy of particles in a sample of material
is temperature a form of energy
NO!!!!!!!!
what are the two temp. scales used in chemistry?
Celsius and Kelvin, the absolute scale
formula for converting from kelvin to celsius
K = C + 273
the temperature during a phase change…
will not change
Matter is a …
…rearrangement of particles of a substance
endothermic phase change
when heat is ADDED to push molecules further apart
exothermic phase change
when heat is released and molecules come closer together
sublimation
phase change from a SOLID to a GAS without the liquid phase
ex: dry ice and solid iodine
what is sublimation caused by?
weak intermolecular forces of attraction –> the bonds between molecules, very weak
intramolecular forces of attraction
bonds BETWEEN atoms, not molecules
triple point
temperature and pressure at which solid, liquid, and vapor phases of a substance coexist in equilibrium.
critical point
between vapor-liquids, above which the two distinct phases do not exist.
deposition
gas to solid
A change in phase is a change in ____ energy
potential
equilibrium phase change
the rate that phase change is occurring from one phase to the other and vice versa is equal
Potential energy is _____ during a single phase
constant
Heat of fusion
amount of heat energy required to change a given amount of solid to a liquid
heat of vaporization
amount of heat energy required to change a given amount of liquid to a gas
melting point is ___ _____ as freezing point
the same`
physical change
the rearrangement of existing particles in a substance
chemical change
bonds are breaking and reforming into new substances, with changed properties.
examples of physical change
- phase changes (subliming)
- dissolving
name the five kinds of chemical reactions
- synthesis (dehydration synth.)
- decomposition
- single replacement
- double replacement
- combustion (burning)
what are the two products of combustion
water and carbon dioxide
chemical changes occur when…
… there is a new substance formed with diff. properties and there is a change in energy
name the five evidences of chemical change
- precipitate forms
- temperature change
- change in color
- solids no longer exist
- production of a gas (bubbling, fizzing)
