CHEM 115 Exam 1

Polyatomic ions, lectures 1-3, charges

NH₄⁺

Ammonium

SO₄^2-

Sulfate

SO₃^2-

Sulfite

NO₃^-

Nitrate

NO₂^-

Nitrite

HCO₃^-

Bicarbonate (or hydrogen carbonate)

HSO₄^-

Bisulfate (or hydrogen sulfate)

HSO₃^-

Bisulfite (or hydrogen sulfite)

H₃O⁺

Hydronium

CN^-

Cyanide

CrO₄^2-

Chromate

Cr₂O₇^2-

Dichromate

CO₃^2-

Carbonate

C₂H₃O₂^-

Acetate

OH^-

Hydroxide

PO₄^3-

Phosphate

PO₃^3-

Phosphite

ClO^-

Hypochlorite

ClO₂^-

Chlorite

ClO₃^-

Chlorate

ClO₄^-

Perchlorate

MnO₄^-

Permanganate

C₂O₄^2-

Oxalate

Law of conservation of mass

During a chemical reaction, mass is conserved.

Law of definite proportions

In a given compound, the elements are always combined in the same ratio by mass.

Dalton’s atomic theory of matter

Matter consists of tiny particles called atoms, which are indestructible. Atoms of the same element are identical in mass and other properties. Atoms of different elements differ in mass and other properties.

Postulates in Dalton’s theory proven incorrect

Atoms are indestructible (smaller pieces of matter within atoms). Atoms of the same element are identical in mass and other properties (isotopes)

Thomson’s cathode ray tubes

Found that atoms consists of parts, one of which is the electron.

Electron charge to mass ratio of electrons

1.76 × 10⁸ C/g

Milliken’s oil droplets

Found that the charge on each droplet was always a whole number multiple of 1.60 × 10^-19 C.

Rutherford’s alpha particles

Found that most of the center of an atom is empty space and contains a massive, positively charged core called the nucleus.

Electron mass

9.109 × 10^-28 g

Proton mass

1.673 × 10^-24 g

Neutron mass

1.675 × 10^-24 g

Isotopes

Atoms of the same element but with different mass. Same number of protons and atomic number but a different number of neutrons. Distinguished by the mass number.

Mass number

Number of protons plus number of neutrons.

1 atom ¹²C —> amu

12 amu

1 amu —> mass of ¹²C atom

1/12 the mass

Groups

Elements in the same column.

Periods

Elements in the same row.

Metals

All elements in the lower left of the dividing line

Properties of metals

Conduct heat and electricity, have luster, are malleable and ductile, and most are solids at room temperature.

Non-metals

Elements to the upper right of the dividing line.

Properties of non-metals

Poor conductors, not malleable or ductile, can be solid, liquid, or gas at room temperature.

Metalloids

Elements bordering the dividing line.

Properties of metalloids

Intermediate properties. Conduct electricity but not as well as metals.

Representative/main group elements

Elements in A groups (1-18).

Transition elements

Elements in B groups (13).

Inner transition elements

Elements in the lanthanide and actinide series (below the periodic table).

Alkali metals

Metals in group IA (Li, Na, K, Rb, Cs).

Properties of alkali metals

Form +1 cations in ionic compounds and oxides are strongly basic.

Alkaline earth metals

Metals in group IIA (Be, Mg, Ca, Sr, Ba).

Properties of alkaline earth metals

Form +2 cations, and oxides are strongly basic but less soluble.

Halogens

Non-metals in group VIIA (F, Cl, Br, I, At).

Properties of halogens

Form -1 cations, exist as diatomic molecules in elemental form at room temperature and chlorides have a salty taste.

Noble gases

Elements in group VIIIA (He, Ne, Ar, Kr, Xe, Rn).

Properties of noble gases

Not very reactive, do not readily form compounds, exist as monatomic gases at room temperature.

Cations

Positively charged ions. Formed by the loss of electrons, # protons > # electrons. Metals tend to form cations in ionic compounds.

Anions

Negatively charged ions. Formed by the gain of electrons. # electrons > # protons. In ionic compounds, non-metals tend to form anions.

Polyatomic ions

Ions consisting of two or more elements. Form covalent bonds, share charge over all atoms in the ion, and all atoms stay together as a unit.

Monatomic ions

Ions consisting of one atom. Charges can be predicted from position on the periodic table.

1 mole

6.022 × 10²⁵ particles

Covalent compounds contain Avogadro’s Number of _____.

Particles

Ionic compounds contain Avogadro’s Number of _____.

Formula units

Microscale

Measure chemicals in terms of atoms, molecules, and formula units. (atomic scale).

Macroscale

Measure chemicals in terms of mole or mass. (g, lb, kg…).

Use Avogadro’s Number when converting from ____ to _____.

Macro to micro or vice versa.

Use molar mass when converting from _____ to _____.

Moles to mass or vice versa. i

Group IA (alkali metals) charge

+1

Group IIA (alkaline earth metals) charge

+2

Group 13 charge

+3

Group 14 charge

±4

Group 15 charge

-3

Group 16 charge

-2

Group 17 charge

-1

Group 18 charge

0

Fe (iron) charge

+2, +3

Cu (copper) charge

+1, +2

Cr (chromium) charge

+2, +3

Mn (manganese) charge

+2, +3

Co (cobalt) charge

+2, +3

Sn (tin) charge

+2, +4

Pb (lead) charge

+2, +4

Zn (zinc) charge

+2

Cd (cadmium) charge

+2

Ni (nickel) charge

+2

Ag (silver) charge

+1

Ammonium (NH₄⁺)charge

+1

Hydroxide (OH^-1) charge

-1

Nitrate (NO₃^-) charge

-1

Sulfate (SO₄^2-) charge

-2

Carbonate (CO₃^2-) charge

-2

Phosphate (PO₄^3-) charge

-3

Acetate (C₂H₃O₂^-) charge

-1

-ide

Ending used for binary compounds containing a metal and nonmetal.

-ate and -ite

Used for polyatomic ions, with -ate indicating a higher number of oxygen atoms and -ite a lower number.

hypo____ite

Used for a compound with 1 occurrence of the anion. (O)

-ite

Used for a compound with 2 occurrences of the anion. (O₂)

-ate

Used for a compound with 3 occurrences of the anion. (O₃)

per____ate

Used for a compound with 4 occurrences of the anion. (O₄)