Exam 1 Study Guide

Question 1

homogeneous mixture

Answer 1

mixture is uniform throughout; ex. salt water

Question 2

heterogeneous mixture

Answer 2

mixture is not uniform throughout; ex. ice cubes in a drink, sand and water.

Question 3

Dalton’s atomic theory

Answer 3

All matter consists of tiny particles called atoms.
An atom cannot be created, divided, destroyed, or converted to any other type of atom.
Atoms of a particular element have identical properties.
Atoms of different elements have different properties.
Atoms of different elements combine in simple whole-number ratios to produce compounds (stable combinations of atoms).
Chemical change involves joining, separating, or rearranging atoms.

Question 4

Convert to C from F

Answer 4

°𝑪 = °𝑭 - 𝟑𝟐 (𝟓/𝟗)

Question 5

Convert to F from C

Answer 5

°𝑭 = °𝐂 (𝟗/𝟓) + 𝟑𝟐

Question 6

Convert to K from C

Answer 6

K = °C + 273.15

Question 7

Convert to C from K

Answer 7

°C = K - 273.15

Question 8

Convert to C from K

Answer 8

°C = K - 273.15

Question 9

Aufbau’s Principle

Answer 9

e- are placed in order of low to high NRG levels (build up principle)

Question 10

Pauli Exclusion Principle

Answer 10

No two e- in an atom can have the atomic orbital (1 spin up and 1 spin down)

Question 11

Hund’s Principle

Answer 11

When filling orbitals that have the same energy, place one e- in each orbital before completing pairs.

Question 12

When are double bonds necessary in a Lewis structure?

Answer 12

If there aren’t enough e- for a full octet after first connecting them with single bonds.

Question 13

Calculation for average atomic mass from two isotopes

Answer 13

avg. atomic mass of element = [(%abundance/100) x (mass in amu)] + [(%abundance/100) x (mass in amu)]

add calculations of the two isotopes

Question 14

n (principle quantum number)

Answer 14

size (distance of the e- from the nucleus

Question 15

l (angular)

Answer 15

shape of the orbital

Question 16

m sub l (magnetic)

Answer 16

orientation of the orbital

Question 17

m sub s (spin)

Answer 17

spin up and spin down

Question 18

e- orbitals

Answer 18

1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p6, 5s2, 4d10, 5p6

Question 19

VSEPR Theory

Answer 19

repulsions between e- groups determine the geometry of a molecule.
lone pair and bonding e- around an atom seek to be as far away from each other as possible.
molecular geometry is determined by the number of e- groups and the max bond angle that can be acheived between the groups.

Question 20

e- geometry for 2 e- groups

Answer 20

linear ( ex. CO2)

Question 21

e- geometry for 3 e- groups

Answer 21

trigonal planar
if lone pairs exists around an atom, the molecular geometry differs from the electron geometry as bent.

Question 22

e- geometry for 4 e- groups

Answer 22

tetrahedral e- geometry
molecular geometry:
one lone pair is trigonal planar
two lone pairs is bent

Question 23

intensive property

Answer 23

property of matter that is independent of the quantity of the substance. Boiling and melting points are intensive properties. For example, the boiling point of one single drop of water is exactly the same as the boiling point of a liter (L) of water.

Question 24

extensive property

Answer 24

depends on the quantity of a substance. Mass and volume are extensive properties. There is an obvious difference between 1 gram (g) of silver and 1 kilogram (kg) of silver; the quantities and, incidentally, the monetary values, differ substantially.

Question 25

mass number

Answer 25

number of protons + number of neutrons

Question 26

number of neutrons

Answer 26

mass number - number of protons (atomic number)

Question 27

ionization energy

Answer 27

the amount of energy required to remove an electron from an isolated atom or molecule.

Question 28

electronegativity order

Answer 28

F > O > N = Cl