Lectures: Test 1 Flashcards

1
Q

What is chemistry?

A

Study of matter, its properties, and its composition.

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2
Q

What is matter and what are its states?

A
Stuff that occupies space: states are
1. Solids: have a definite shape
2. Liquids: atoms are close together but have no definite shape; also has a "top," or a surface.
3. Gases: atoms very spread apart
[4. plasma: just ions everywhere]
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3
Q

What are physical properties?

A

Properties of a substance that do not concern interactions with other chemicals.

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4
Q

What are chemical properties?

A

Properties of a substance regarding its interaction with other chemicals.

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5
Q

What is the difference between a physical and a chemical change?

A
  1. Physical changes are reversible and do not alter the composition of the substance [such as state changes].
  2. Chemical changes are not [easily] reversible and do involve composition change [such as hydrolysis where H2O becomes H2 and O2
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6
Q

What is energy? PE? KE?

A
  1. PE: due to position of object
  2. KE: due to movement of object
  3. Total energy: PE + KE; is the ability to do work.
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7
Q

What is the relationship between energy state and stability?

A

Lower energy states are more stable and are preferable.

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8
Q

What are the 7 fundamental [SI] units?

A

mass: kilogram [kg]
length: meter [m]
time: seconds [s]
temperature: kelvin [K]
amount: mol
current: ampere [A]
luminous density: candle [cd]

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9
Q

Given magnitude and symbol for the following prefixes

  1. mega
  2. kilo
  3. centi
  4. milli
  5. micro
  6. nano
A
  1. M = 10^6
  2. k = 10^3
  3. c = 10^-2
  4. m = 10^-3
  5. μ = 10^-6
  6. n = 10^-9
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10
Q

What is one mL in SI units?

A

1 cm^3

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11
Q

A conversion factor is _____, and the factor label system is _____

A
  1. a ratio of equivalent quantities.

2. dimensional analysis: use of conversion factors to convert one unit to another.

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12
Q

Density is _____

A

mass / volume

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13
Q

How to convert from C to F to K?

A
  1. K = C + 273.15

2. F = 9/5 C + 32

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14
Q

What is the difference between intensive and extensive properties?

A
  1. Intensive properties don’t change with amount of substance.
  2. Extensive properties do change with amount.
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15
Q

Classify the following as intensive or extensive properties:

density, melting point, mass, energy, boiling point, color, volume.

A
  1. density is intensive
  2. melting point is intensive
  3. mass is extensive
  4. energy is extensive
  5. boiling point is intensive
  6. color is intensive
  7. volume is extensive
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16
Q

What is the difference between precision and accuracy?

A
  1. Precision means data is close together

2. Accuracy means data is close to accepted value.

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17
Q

What are random errors vs. systematic errors?

A
  1. Random refers to low precision, low accuracy.

2. Systematic refers to high precision, low accuracy.

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18
Q

One angstrom is _____

A

10^-10 m

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19
Q

What is an element?

A

pure substances: only one kind of atom.

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20
Q

What are the seven diatomics?

A

H2, O2, N2, F2, Cl2, Br2, I2

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21
Q

What are compounds?

A

chemical combinations of 2 or more elements with chemical bonds. Can only be separated with chemical reactions.

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22
Q

What are mixtures?

A

combination of elements without chemical bonds. They retain the properties of individual components and you can separate them physically.

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23
Q

The law of conservation of mass says _____

A

mass is never created or destroyed. During chemical reactions, no mass is lost.

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24
Q

The law of definite composition says _____

A

any compound is composed of the same elements in the same parts [fractions] by mass.

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25
Q

The law of multiple proportions says _____

A

elements A and B react to form two compounds. The different masses of A and B can be expressed as a ratio of small whole numbers

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26
Q

What did John Dalton do?

A

Made the atomic theory.

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27
Q

What are the postulates of the atomic theory?

A
  1. All matter is atoms: indivisible units.
  2. Atoms of one element cannot be converted to another (through chemical reactions).
  3. Atoms of one element are identical to every other in mass and other properties.
  4. Compounds result from chemical combinations of a specific ratio of atoms of different elements. (per law of definite composition).
28
Q

What did JJ Thompson do?

A
  1. Developed plum-pudding model.

2. Measured ratio of mass of cathode ray particles to the charge.

29
Q

What are cathode rays?

A

string of negatively charged particles determined to go from a negatively charged plate to a positively charged one.

30
Q

What did Robert Millikan do?

A

Measured charge of electron with his “oil-drop” experiment. Found electrons have a negligible mass.

31
Q

What did Ernest Rutherford do?

A

Tested the plum-pudding model with the gold-foil experiment. Determined that atoms have positively charged particles in a “nucleus.”

32
Q

What did James Chadwick do?

A

discovered the neutron; measured the mass of protons; neutron have the same mass as protons.

33
Q

Atomic symbol of an element refers to _____

A

The letter or combination of letters signifying one particular element.

34
Q

The atomic number refers to _____

A

the umber of protons in the nucleus of an element.

35
Q

Number of electrons in an atom may be determined from the _____ number

A

atomic

36
Q

What is required to determine the number of neutrons in the nucleus of an atom?

A

The mass number and the atomic number

37
Q

The mass number is ____

A

The number of neutrons plus the number of protons in the nucleus of an atom.

38
Q

Two atoms are isotopes when _____

A

they have the same atomic number but different mass numbers; aka they have different numbers of neutrons in their nuclei.

39
Q

The percent abundance of isotopes is determined via _____

A

mass spectrometry

40
Q

Avg. atomic mass is determined by the following equation: _____

A

avg atomic mass = Σ (isotope mass) x (% abundance / 100)

41
Q

The main group elements consist of _____

A

On the periodic table, groups 1, 2, and 13-18

42
Q

The transition elements consist of _____

A

groups 3-12 on the periodic table.

43
Q

The alkali metals are group _____ and consist of elements _____. Their common property is that they are _____

A
  1. 1
  2. Lithium, sodium, potassium, rubidium, cae­sium, and francium
  3. Extremely reactive.
44
Q

The alkaline earth metals are group _____ and consist of elements _____.

A
  1. 2

2. Beryllium, magnesium, calcium, strontium, barium, and radium.

45
Q

The metalloids are elements _____

A

boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), astatine (At).

46
Q

Elements to the right of the metalloids on the periodic table are _____, while those the left are _____

A
  1. Nonmetals

2. Metals

47
Q

The noble gases are group _____ and consist of elements _____

A
  1. 18

2. the inert gases: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radeon (Rn)

48
Q

The halogens are the group _____ and consist of elements _____

A
  1. 17

2. reactive nonmetals: fluorine (F), chlorine (Cl), bromine (Br), and iodine (I)

49
Q

What are valence electrons?

A

Those on the outermost shell / orbital of the atom

50
Q

What are compounds?

A

Two or more different elements in a chemical bond: only valence electrons are relevant for chemical bonds.

51
Q

An ionic bond occurs when _____

A

A metal atom gives up an electron (making it an anion) to a nonmetal (making it a cation) so the two [almost] complete their outermost electron shells. The two ions are then forced together via electromagnetic attraction.

52
Q

Covalent bonds occur when _____

A

Electrons are shared between two nonmetals: both atoms want more electrons so neither gives its electrons up. Instead, they share.

53
Q

Covalent bonds occur between two ______.

A

Nonmetals

54
Q

What is a monatomic ion?

A

One atom; an ion that is one atom.

55
Q

What is a polyatomic ion?

A

An ion consisting of two or more atoms: like CO^2-, _3

56
Q

List the common positively charged monatomic ions, the formulas and names.

A
Cations:
H+ hydrogen
Li+ lithium
Na+ sodium
K+ potassium
Cs+ cesium
Ag+ silver
Mg(2+) magnesium
Ca(2+) calcium
Sr(2+) strontium
Ba(2+) barium
Zn(2+) zinc
Cd(2+) cadmium
Al(3+) aluminum
57
Q

List the common negatively charged monatomic ions, the formulas and names.

A
Anions:
H- hydride
F- fluoride
Cl- chloride
Br- bromide
I- iodide
O(2-) oxide
S(2-) sulfide
N(3-) nitride
58
Q

List the common metals that form more than one monatomic ion; the formula, systematic name, and common name.

A
Cr(2+) chromium(II) chromous
Cr(3+) chromium(III) chromic
Co(2+) cobalt(II) N/A
Co(3+) cobalt(III) N/A
Cu(+) copper(I) cuprous
Cu(2+) copper(II) cupric
Fe(2+) iron(II) ferrous
Fe(3+) iron(III) ferric
Pb(2+) lead(II) N/A
Pb(4+) lead(IV) N/A
Hg_2 (2+) mercury(I) mercurous
Hg(2+) mercury(II) mercuric
Sn(2+) tin(II) stannous
Sn(4+) tin(IV) stannic
59
Q

List the common polyatomic ions.

A
NH_4(+) ammonium
H_3O(+) hydronium
CH_3COO(-) acetate
CN(-) cyanide
OH(-) hydroxide
ClO(-) hypochlorite
ClO_2(-) chlorite
ClO_3(-) chlorate
ClO_4(-) perchlorate
NO_2(-) nitrite
NO_3(-) nitrate
MnO_4(-) permanganate
CO_3(2-) carbonate
HCO_3(-) hydrogen carbonate
CrO_4(2-) chromate
Cr_2O_7(2-) dichromate
O_2(2-) peroxide
PO_4(3-) phosphate
HPO_4(2-) hydrogen phosphate
H_2PO_4(-) dihydrogen phosphate
SO_3(2-) sulfite
SO_4(2-) sulfate
HSO_4(-) hydrogen sulfate
60
Q

What is molecular mass?

A

Sum of atomic masses

61
Q

What is the rounding rule for calculating molecular mass

A

Never round

62
Q

What is stoichiometry

A

Study of quantitative aspects of formulas and reactions

63
Q

What is a mole?

A

1 mol = an amount of atoms = Avogadro’s number of atoms (or molecules) = 6.022x10^23

64
Q

What is molar mass

A

g/mol = number under the atomic symbol on the periodic table

65
Q

How to convert from mass to mol?

A

Divide given mass by the molar mass

66
Q

How to convert from mol to # of molecules?

A

Multiply x mol by Avogadro’s number

67
Q

How to convert from number of molecules to mols to mass?

A

Divide # of molecules by Avogadro’s number to get mols. Times by molar mass to get mass.