Gen Chem 1: Chapter 3: From Elements to Compounds

ion

an atom or group of atoms that has an overall charge

atoms GAIN or LOSE electrons to obtain SAME number of electrons as nearest ___ ____

noble gas

isoelectronic

having same number of electrons

cation

positively charged ion (LOSE e-)

METALS tend to _____ (gain/lose) electrons, forming ______ (cations/anions)

METALS tend to LOSE electrons, forming CATIONS

Group 1A forms ____ ions

1+

Group 2A forms ___ ions

2+

Group 3A forms ____ ions

3+

Transition metals’ charges typically range from ____ to _____

1+ to 4+

name Na⁺

sodium ion

name Mg²⁺

magnesium ion

transition metals’ with more charges names include ____ ____

roman numerals

name Fe²⁺ and Fe³⁺

Fe²⁺: iron (II)

Fe³⁺: iron (III)

anion

negatively charged ion (GAIN e-)

NONMETALS tend to _____ (gain/lose) electrons, forming ______ (cations/anions)

NONMETALS tend to GAIN electrons, forming ANIONS

Group 5A forms ____ ions

3-

Group 6A forms ____ ions

2-

Group 7A forms ____ ions

1-

when naming anions, add ___ suffix

-ide suffix

name Cl^-

chloride

name S^2-

sulfide

polyatomic ions

a group of atoms with an overall charge

oxyanion

negatively charged polyatomic ion that contains oxygen

oxyanions’ usual suffix

-ate

name CO₃^-

carbonate

MORE oxyanions’ suffix:

FEWER oxyanions’ suffix:

MORE oxyanions’ suffix: -ate

FEWER oxyanions’ suffix: -ite

name NO₃^-

name NO₂^-

NO₃^- — nitrate

NO₂^- — nitrite

per- prefix in a polyatomic anion means

MORE

hypo- prefix in a polyatomic anion means…

LESS

Cuolomb’s Law

1. force of attraction DIRECTLY proportional to charges on two particles (INC charge —> INC force)

2. force of attraction INVERSELY proportional to square of distance between two particles (DEC distance —> INC force; CLOSER —> FORCE)

ionic bond

attraction btwn oppositely charged ions

ionic compound

a cmpd composed of charged ions

metal cations + nonmetal anions = ionic compound

ionic lattice

array of pos & neg ions

empirical formula

chemical formula that gives SMALLEST whole-number ratio of atoms in compounds

formula unit

in an ionic compound, SMALLES number of ions necessary to form a compound

write K⁺ and S^2-

K₂S

write Ca²⁺ and NO₃^-

Ca(NO₃)₂

write Al³⁺ and SO₄^2-

Al₂(SO₄)₃

name MgCl₂ (main group ionic cmpd)

magnesium chloride

name CuCl and CuCl₂ (transition metal ionic compound)

CuCl - copper (I) chloride

CuCl₂ - copper (II) chloride

name MgSO₄ (ionic compound containing polyatomic)

magnesium sulfate

hydrate

an ionic solid containing a fixed ratio of water in the crystal structure

prefixes for hydrates

mono

di

tri

tetra

penta

hexa

hepta

octa

nona

deca

name NiCl₂ × 6H₂O

nickle (II) chloride hexahydrate

covalent bond

electrons shared btwn 2 nonmetals

Diatomic Molecules

H₂

N₂

F₂

O₂

I₂

Cl₂

B₂

single bonds are held together by _____ bond

sigma bond

single bonds occur along _____ ____ btwn nuclei

internuclear axis

double bond

• 1 sigma + 1 pi

• sigma + pi beats strong sigma

• SHORTER and STRONGER than single bond

• occurs above and below internuclear axis

is sigma or pi bond stronger?

sigma bond is stronger

triple bond

• 1 sigma, 2 pi bonds

• SHORTEST and STRONGEST

molecular formula

tells you # of atoms in molecule

when naming covalent compounds, the first element is the one on the ___ on the periodic table

FIRST — LEFT

aqueous solution

homogenous solution, main component is water

electrolyte solution

aqueous solution with containing dissolved ions

dissociation

ions pull apart from crystal lattice in aqueous solution

do they produce electricity?

1. ionic cmpds

2. acids

3. molecular cmpds

1. ionic cmpds - YES

2. acids - SLIGHTLY (dim)

3. molecular cmpds - NO

acids produce some electricity because they…

dissociate(ionize) in water

ex: HCl(aq) —> H⁺(aq) + Cl^-(aq)

-ic acids form -__ bases

-ic acids form -ate bases

-ous acids form -___ bases

-ous acids form -ite bases

elemental analysis

lab techniques used to determine cmpd’s empirical formula and percent composition

combustion analysis

type of elemental analysis in which a substance in oven & burned

1. C atoms from CO₂

2. H atoms form H₂O

mass spectrometry

technique used to measure molecular mass

mass spectrometry calculates ions based on… (3 components)

1. size of electric field

2. charge on ion

3. curvature of ion

mass spectrometry equation

molecular mass/empirical mass = n (n is an integer)