chemistry unit 4b

induced dipole forces

if one atom either develops, or already possesses a dipole, it can force the atoms around it to also develop a dipole by repelling the electrons around its negative pole and attracting them towards its positive

what is epson salt (MgSO4)

ionic substance

what are diamonds?

network covalent substance

what is carbon dioxide?

nonpolar covalent substance

what is the strongest attractive force being overcome when liquid water boils

hydrogen bonds

dipole-dipole interactions

-atoms w a dipole moment will interact with each other by the attraction of their negative pole and positive pole -explains why molecules w very few electrons have more condensed states of matter

covalent nomenclature

-dont put mono as a prefix on the first element -last element gets the suffix "ide"

exceptions to the octet rule

-elements that are stable w less than an octet (<6) -elements that are stable w more than an octet -after Mg?

covalent compounds

-form between atoms -atoms share electrons in their valence shells -weaker intramolecular attraction because the electrons of one atom still repel the electrons of the bonded atom, and the nuclei repel one another as well. only the attraction of the bonded electrons, for the nucleus of the bound atom hold the bond together.

ionic compounds

-form between ions -electrons are transferred between atoms, cations donate electrons to anions -the strongest of intramolecular forces

types of covalent bonds

-network covalent bonds -exist as a repeating pattern -examples: sand (SIO2), diamonds -molecular covalent molecules -exist as individual molecules -examples: water, ammonia, sugar

hydrogen bonds

-not actual bonds -strongest of all IMFs -only with FON -h= negative -fon= positive -high boiling point

electron dot diagram

-pictorial representation of the valence electrons of an atom

lewis structures

-pictorial representations of molecular covalent bonds

intermolecular forces

-the attraction between molecules that are responsible for a substances state of matter -the stronger the imf, the higher the melting point of a solid, boiling poiint of a liquid, stronger surface tension and cohesive and adhesive forces

hybridization

-the number of regions of electron density determines which orbitals need to merge to accommodate the increase in the numbers of electrons sp: 2 reg sp2: 3 sp3: 4 sp3d: 5 sp3d2: 6

london dispersion forces

-the weakest attraction -based on electron movement. at any given moment the electrons could pile up on the side of the atom producing a momentary dipole -the more electrons the stronger these forces become

pre named nomenclature for water ammonia methane diamonds and graphite

-water: dihydrogen monoxide, hydrogen oxide, hydrohydroxic acid -ammonia: nitrogen trihydride, NH3 -methane: carbon tetrahydride, CH4 -diamonds, graphite: carbon

polarity

-when electrons arent shared equally between the bonded atoms. -based on electronegativity, F is the most electronegative, and it decreases as you move away from it -elements w high electronegativities will attrqact electrons more thus making them slightly negative. they pull electrons towards them leaving less electronegative atoms with fewer electrons around them, making them slightly positive

the HOH bond angle in a water molecule, H2O, is closest to

107

prefixes

1: mono 2: di 3: tri 4: tetra 5: penta 6: hexa 7:hepta 8: octa 9: nona 10:deca

what elements can form double or triple bonds

CNOPS

what is the formula of ammonia

NH3

which of the following compounds is incorrectly paired a. NO2- mononitrogen dioxide b. Se5O10- pentalselenium decoxide c. PCl3- phosphorus trichloride d. SF6- sulfur hexafluoride

a

which of the following has the least polar bond? a, F2 b. HCl c. CH3Br d. NCl3

a

what is the formula of a compound whose nomenclature is silicon disulfide? a. Si2S b. SiS2 c. 2SiS d. Si2S

b

what shape best describes a BrF4- ion a. tetrahedral b. square planar c. see saw d. trigonal planar

b

which of the following doesnt satisfy the octet rule? a. H2O b. BI3 c. NO2 d. CH4

b

which of the following is nonpolar a. H2O b. BF3 c. NF3 d. HF

b

which of the following names doesnt describe H2O a. dihydrogen monoxide b. hydrogen dioxide c. hydrogen hydroxide d. water

b

sigma bonds

bonded electrons that orbit between the nuclei of each atom in the plane of the nuclei. (first line/bond)

polar compounds can dissolve all of the following except a. polar compounds b. ionic salts c. nonpolar compounds d. alcohols

c

which of the following is both linear and polar? a. HCN b. CCl4 c. N2 d. H2S

c

which of the following molecules is a trigonal pyramid a. CF4 b. SCl6 c. PF3 d. PCl5

c

which of the following molecules is inconsistant w the hybridization state a. NH3, sp3 b. PI5, sp3d c. XeS4, sp3 d. SO2, sp3

c

which of the following statements regarding chemical bonding is false a. ionic solids are held together by electrostatic forces b. covalent molecules are held together by sharing electrons c. the total number of valence electrons for CCl4 is 34 d. covalent molecules may not share electrons equally

c

all of the following guidelines apply to drawing lewis structures of covalent compounds except a. only elements C,N,O,P,S may form double bonds b. h can never be the central atom of a covalent compound c. elements w a principle quantum number greater than 3 may have an expanded octet d. halogens are never the central atom of a covalent compound

d

what is the formula of diarsenic heptoxide a. As7O2 b. As2O6 c. As6O2 d. As2O7

d

which of the following compounds contains both ionic and covalent bonds a. (PO4)3- b. NH3 c. MgF2 d. MgSO3

d

which of the following exhibits hydrogen bonding a. BH3 b. HCl c. NF3 d. C2H5OH

d

which of the following would you expect to have the highest boiling point a. Ne b. F2 c. CO2 d. CH4

d

all of the following are true of polar compounds except a. they usually have higher boiling points than nonpolar substances b. they dissolve polar compounds as well as ionic salts c. they have areas of high electron density d. they are comprised of metals and nonmentals

d (this could be wrong)

pi bonds

double/triple bonds

how is the type of bond determined?

electronegativity. -based largely on size. ionic bonds: form when the difference in electronegaitvity is greater than 1.7, because the greater electronegative atom attracts the electrons so much that they leave the less electronegative atom forming ions covalent bonds: -non polar cov bonds occur when the diff in electronegativity is less than 0.4, this causes the bound electrons to be shaared equally -polar cov bonds occur when the diff in electronegativity is between 0.4 and 1.7/ the bound electrons favor one atom over another causes them to develop a partial positive and parital negative charge. the greater the difference in electronegativity, the more polar the bond