Chapter 2 Sections 9-10
Review : Nomenclature
- Acids and Bases (section 2.9)
- Acids - molecules that can lose H+ (proton donors) in water making
H3O+(aq) in water. Note H+(aq) is
really just short hand for H3O+(aq). Also
note that (aq) means dissolved and surrounded by water. If there are H+(aq)
ions called hydronium ions present, then the solution is acidic.
- Know these acids: HCl, HNO3 and H2SO4.
Hydrochloric, nitric and sulfuric.
- Reactions looks like this: HCl(g) +H2O(l) g
H3O+(aq) + Cl-(aq)
- Remember people that take acid are losers - so acids LOSE H+
- Bases - molecules than can gain H+ (proton acceptors)
and/or make OH- in water. If there are OH-(aq)
ions present called hydroxide ions, then the solution is basic.
- Know these bases: NaOH, KOH, Ba(OH)2 which are
all solids
- Reactions looks like this when put in water: NaOH(s) g
Na+(aq) + OH-(aq)
- Try Problem 2.14
- Why are these dissolving in water in the first place? Well
because the sum of all the ion-dipole forces created by having the ions
surrounded by water are greater than the original ionic or covalent
bond. Not all acids and bases dissolve in water so easily! You'll
learn a lot more in second semester.
- Nomenclature (section 2.10) SUPER
IMPORTANT
- Ionic Compounds
- Why do they form in the first place? Well remember that each
atom's goal is to be s2p6 and to get there
they must lose or gain electrons (except the Noble Gases) and then
they are cations or anions with an oxidation state. Review
it here! IMPORTANT
- You MUST be able to put ionic formulas together so that the
charges sum to zero. Practice
is below this outline. DO IT!
- name of metal cation + name of nonmetal anion + ide
- Examples
- NH4Cl - ammonium chloride
- CaCO3 - calcium carbonate
- NaOH - sodium hydroxide
- MgO - magnesium oxide
- Li3P - lithium phosphide
- CaBr2 calcium bromide
- Na2S - sodium sulfide
- Mg3(PO4)2 - magnesium
phosphate
- Na2SO4 - sodium sulfate
- Transition metal compounds
- name of transition metal, (charge in Roman numerals) + name of
nonmetal + ide
- Why the Roman numeral? Well the oxidation state of most
transition metals varies - so we have to indicate what it is.
- Examples
- Fe2O3 - iron(III) oxide
- AgCl - silver(I) chloride
- CuS - copper(II) sulfide
- Co(NO3)3 - cobalt(III) nitrate
- FeSO4 - iron(II) sulfate
- Zn(OH)2 - zinc(II) hydroxide
- iron(III) flouride - FeF3
- iron(II) phosphate - Fe3(PO4)2
- Look at examples 2.9 and
2.10. Try problems 2.15 - 2.17.
- Remember you are supposed to know all these atom's names: H, He,
Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Cr,
Mn, Fe, Co, Ni, Cu, Zn, Br, Kr, Sr, Ag, Sn, I, Ba, Au, Hg, Pb and
U IMPORTANT
- Hey - Ag is always +1, Zinc and
Cadmium are always +2 so you don't need to use a Roman Numeral with
them: AgCl is silver chloride, Zinc fluoride is ZnF2,
Ag2S is silver sulfide
- Covalent Compounds
- prefix name of least electronegative nonmetal + prefix name of
most electronegative nonmetal
- prefixes are mono, di, tri, tetra, penta, hexa, hepta, octa (mono
is ommitted from the first element)
- Examples
- CO2 - carbon dioxide
- CO - carbon monoxide
- PCl5 - phosphorus pentachloride
- SF4 - sulfur tetraflouride
- P2O5 - diphosphorus pentoxide
- SiO2 - silicon dioxide
- H2O2 - dihydrogen dioxide
- nitrogen monoxide - NO
- carbon tetrachloride - CCl4
- nitrogen trihydride - NH3
- iodine heptaflouride - IF7
- Look at example
2.11. Try problems 2.18 and 2.19
- Ionic compounds with polyatomic ions
- treat polyatomic ions as groups that always stay together
- never change the name of the polyatomic ion, otherwise name as
ionic compounds
- Memorize these: NH4+, CH3COO-,
CN-, HCO3-, OH-,
MnO4-, NO2-,
NO3-, CO32-,
SO42-, SO32-,
PO43- Find their names in Table
2.3. IMPORTANT
- NaOH is sodium hydroxide, Ca(NO3)2 is
calcium nitrate, MgSO4 is magnesium sulfate
- ammonium sulfide is (NH4)2 S, calcium
carbonate is CaCO3, magnesium phosphate is Mg3(PO4)2
- Oxoanions - different numbers of oxygens
- Know hypochlorite, chlorite, chlorate, perchlorate
- Try example 2.12 and 2.13. Try problems 2.20, 2.21, 2.22.
- Oxoacids
- Know hypochlorous, chlorous, chloric, and perchloric acids
- Know nitrous and nitric acids
- Learn them in Table
2.4. Try example 2.14 and problem 2.23
Final Notes - At this point in time you should be able to:
- Given any covalent molecule, you should be able to draw the Lewis dot
structure, tell the molecular shape, electron geometry, hybridization and bond angles, name the
molecule, tell if
the bonds are polar or not, and tell if the entire molecule is polar or
not.
- Given any group 1 or 2 metal, and a nonmetal, you should be able to
predict the formula of the resulting ionic compound, know the oxidation
states on
the ions, and name the compound.
- Be able to name a transition metal compound.
Practice!!!
Ya Hoo!!!
- Predict the most common oxidation state for the ions the following elements
form: Li, S, Cs, Al, Br, N, Mg, K, P, Bi, F, Ne, Ba, Pb, As, Te.
- How many electrons total do the noble gases have?
- What will the following atoms do in order to be like a noble gas? Ga,
F, I, Be, K
- Predict the ionic compound formulas for the following pairs of
elements. (Assume they can make an ionic compound) Li and Cl, K
and S, Na and P, Mg and Br, Ca and S, Ba and N, Al and F, Ga and O, In and
P, Pb and F, Pb and O, Bi and Cl, Bi and S, Po and F
- What makes the noble gases so stable?
- What is the difference between an ionic and covalent bond?
- If an atom has more protons than electrons what is it called?
- Ionic compounds are held together by ionic bonds which are basically
____________ attractions between ions.
- Name all the elements that form covalent bonds with themselves and give their formulas.
- Why does hydrogen occur naturally as H2?
- Name the following ionic compounds: KI, AlBr3, MgSO4,
Na3PO4, LiCH3COOH, Fe(CN)2,
Ni(HCO3)3, KOH
- Give the chemical formulas for the following ionic compounds:
calcium nitrate, lithium iodide, sodium carbonate, ammonium nitride
- Name the following covalent compounds: CO, PI5, IF7,
SiF4
- Write chemical formulas for the following covalent compounds:
nitrogen trihydride, silicon tetrabromide, sulfur dihydride
- Name the following compounds: KNO3, N2O5
NaBr, PH3, MgS, Ca(OH)2, CS2, NH4I,
LiF, (NH4)2CO3, PCl5
- Write chemical formulas for the following: dihydrogen disulfide,
lithium nitride, calcium phosphide, nitrogen tribromide, magnesium nitride,
sodium iodide, sulfur tetrahydride, potassium phosphate, silver
permanganate, zinc nitrite, sodium sulfite
Answers:
- Li is +1, S is -2, Cs is +1, Al is +3, Br is -1, N is -3, Mg is +2, K is
+1, P is -3, Bi is +5, F is -1, Ne does not make ions, Ba is +2, Pb is +4,
As is +5 or -3, Te is +6 or -2.
- 2, 10, 18, 36, 54 and 86.
- Ga will lose 3 electrons to become Ga+3, F will gain one
electron to become F-, I will gain one electron to become I-,
Be will lose two electrons to become Be+2, K will lose one
electron to become K+.
- Li and Cl make LiCl, K and S make K2S, Na and P make Na3P,
Mg and Br make MgBr2, Ca and S make CaS, Ba and N make Ba3N2
(Ba is +2 and N is -3 so we need three Ba's to make +6 and we need two N's
to make -6 because +6-6 = 0), Al and F make AlF3, Ga and O make
Ga2O3, In and P make InP, Pb and F make PbF4,
Pb and O make PbO2, Bi and Cl make BiCl5, Bi and S
make Bi2S5 (S is -2 while Bi is either +5 or -3.
Since S is already negative, Bi must be positive. We need five S's to
make -10 and we need 2 Bi's to make +10), Po and F make PoF6
(Here Po will be +6 instead of -2 since it is bonding with F which is
negative)
- The have full outer s and p subshells = 8 electrons. Except helium
which just has the full 1s with 2 electrons.
- An ionic bond involves the transfer of electrons from a metal to a
nonmetal. A covalent bond involves the sharing of electrons between 2
or more nonmetals.
- cation
- electrostatic
- hydrogen occurs naturally as H2, Nitrogen occurs naturally as N2,
Oxygen as O2, Fluorine as F2, Chlorine as Cl2, Bromine
as Br2, Iodine as I2, and just for fun Phosphorus as P4,
Sulfur as S8 and Selenium as Se8
- Each hydrogen atom has only one electron so it is not stable. H
wants to have 2 electrons to be like helium. If two H atoms come
together they can share their electrons so that each H then has 2
electrons. So then each H is stable and like a noble gas. H :
H
- potassium iodide, aluminum bromide, magnesium sulfate, sodium phosphate,
lithium acetate, iron(II) cyanide, nickel(III) bicarbonate, potassium
hydroxide
- Ca(NO3)2, LiI, Na2CO3, (NH4)3N
- carbon monoxide, phosphorus pentaiodide, iodine heptafluoride, silicon
tetrafluoride
- NH3, SiBr4, SH2
- potassium nitrate, dinitrogen pentoxide, sodium bromide, phosphorus
trihydride, magnesium sulfide, calcium hydroxide, carbon disulfide, ammonium
iodide, lithium flouride, ammonium carbonate, phosphorus pentachloride
- H2S2, Li3N, Ca3P2,
NBr3, Mg3N2, NaI, SH4, K3PO4,
AgMnO4, Zn(NO2)2, Na2SO3
We have now
finished Chapter 2 completely. Study Hard.
Recommended
problems: 74,
78, 82, 84, 86, 104, 110