S1.1 Flashcards

the particulate nature of matter

1
Q

atom

def

A

= the smallest units of matter that still possess certain chemical properties

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2
Q

elementary substances

A

contain atoms of a single element

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3
Q

elements

def

A
  • = the primary constituents of matter, which cannot be broken down into simpler substances
  • made up of the same atoms, or atoms with the same number of protons
  • simplest form of matter
  • can exist as individual atoms (f.i. Fe) or atoms, which are bonded together (H2)
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4
Q

compounds

def

A
  • consist of atoms of different elements, which are chemically bonded together in a fixed ratio and have different properties from the constituent elements
  • constituents cannot be separated using physical methods, only chemical
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5
Q

The composition of matter (A. Einstein)

A

E = mc^2
E … energy (small value)
m … mass (negligible value)
c … speed of light (large value) = 3.0⋅10^8 ms

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6
Q

division of matter

A
  • pure substances: elements, compounds
  • mixtures: homogenous, heterogenous
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7
Q

classifications of matter

A
  • has a mass
  • occupies a volume in space
  • made up of particles, atoms, molecules or ions
  • particles are in constant motion
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8
Q

pure substances

def, division

A

= matter with definite and constant composition
division: elements, compounds

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9
Q

mixtures

def, division

A
  • = matter, which is a combination of two or more pure substances (in no fixed ratio) that retain their individual properties
  • constituents are not chemically bonded, can be separated using physical methods
  • division: homogenous, heterogenous
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10
Q

homogeneous mixture

A

⇒ uniform composition and properties throughout
no visible phases or boundaries

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11
Q

heterogeneous mixture

A

⇒ non-uniform composition, varying properties throughout
visible phases/boundaries

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12
Q

methods of separation

A
  1. filtration
  2. evaporation
  3. solvation (dissolution)
  4. distillation
  5. paper chromotography
  6. (re)crystallization
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13
Q

filtration

A
  • = the separation of an insoluble solid from a liquid or solution in a heterogeneous mixture
  • filtrate = the liquid/solution which is able to pass through the filter paper
  • residue = the insoluble solid which remains on the filter paper
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14
Q

evaporation

A
  • ⇒ the solution is heated in an evaporating dish → the solvent evaporates, leaving the solute behind (as the residue)
  • volatile liquids are removed, solids are left
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15
Q

solvation (dissolution)

A
  • = the separation of a heterogeneous mixture of two solids based on differences in solubility, which can be then separated by filtration or evaporation
  • soluble substances are removed, insoluble are left
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16
Q

distillation

A
  • = the separation of a liquid mixture based on the difference in volatility or boiling points between the components of the mixture
  • volatile liquids are removed, non-volatile ones are left
17
Q

volatility

A

= the tendency of a substance to undergo evaporation

18
Q

paper chromotography

A
  • used to separate a mixture of solutes in a solvent
  • mobile phase = solvent undergoing separation
  • stationary phase = the chromatography paper used
  • the components of the mixture move through the stationary phase at different rates due to their differences in solvation
19
Q

HPLC

A
  • high pressure/performance liquid chromotography
  • mobile phase is liquid
  • faster
  • only a small sample is needed
20
Q

crystallization

def, based on

A
  • = the process of forming solid crystals from a solution
  • based on the varied solubilities of solids at different temperatures
21
Q

recrystallization

def, based on

A
  • = a separation technique, which is used to remove impurities that are mixed in with a solid
  • based on the varied solubilities of solids at different temperatures
22
Q

methodology of recrystallization

A
  1. dissolve the impure mixture in a volume of hot solvent that is just enough to completely dissolve it ⇒ insoluble impurities can be filtered off
  2. the solution is cooled to room temperature which causes the solubility of the dissolved solids to decrease ⇒ formation of crystals, leaving the soluble impurities in the solution, which are then filtered to obtain the pure product

cover with a watch glass in order to prevent evaporation and contamination

23
Q

kinetic molecular theory

A
  • all matter is made up of small particles
  • all particles have kinetic energy ⇒ they are all constantly moving
  • the amount of kinetic energy is proportional to the temperature of the substance ⇒ particles have greater motion at higher temperatures
  • collisions between particles are elastic (no loss of kinetic energy)
24
Q

states of matter

A

solid
liquid
gas
plasma

25
solids | kin energy, space between particles, V, shape, f of attr., density
* least amount of kinetic energy * particles are very close together with little space between them ⇒ cannot be compressed * fixed V, shape * strong forces of attraction between particles * particles vibrate in fixed positions but do not move around * tend to have higher density
26
liquid | particle placement, f of attr., V, shape
* particles are close together with some space between them ⇒ can flow, move more freely * forces of attraction exist, yet are weaker than in a solid * fixed V, no fixed shape ⇒ take the shape of the bottom of the container * cannot be compressed * particles vibrate, rotate and move around
27
p(H2O) | density
1 g/cm^3 1000 kg/m^3
28
gasses | V, shape, f of attr, particle placement, kin energy
* no fixed V or shape ⇒ take on the same shape of the container itself, can be compressed * attractive forces between particles are negligible * particles are far apart with lots of space between them * most amount of kinetic energy * particles vibrate, rotate, and move around faster than in a liquid
29
plasma
* = ionized gas mostly found in space * atoms in plasma become increasingly ionized * free electrons move among positively charged ions
30
endothermic phase changes
* melting (solid to liquid) * vaporization (liquid to gas) * sublimation (solid to gas) | absorb energy/heat => to break bonds
31
exothermic phase changes
* freezing (liquid to solid) * condensation (gas to liquid) * deposition (gas to solid) | release energy/heat => to form stronger bonds
32
vaporization vs boiling vs evaporation
* **vaporization** ⇒ the general process of a liquid becoming a gas and can happen through evaporation and boiling * **evaporation** ⇒ only at the surface of a liquid; doesn’t have to reach the boiling point * **boiling** ⇒ throughout the liquid * at a specific temperature; when vapor pressure reaches external pressure
33
Kelvins
* SI unit of temperature * absolute zero ⇒ the movement of all particles stops (T = 0K = -273°C) * T(K) = T(°C) + 273.15