gen chem 2

vocabulary and other things that should be committed to memory !

domain

number of different electron groups

how do you know which element to pick for the center?

its the least electronegative element

duet rule

hydrogen can only form 1 bond, as it cant have more than 2 electrons

what is the electron geometry when there are 2 domains

linear

what is the bond angle for a structure that is linear?

180 degrees

what is the electron geometry when there are 3 domains?

trigonal planar

what is the electron geometry when there are 4 domains

tetrahedral

what is the bond angle for a trigonal planar structure?

120 degrees

what is the bond angle for a tetrahedral structure?

109.5 degrees

at what amount of domains does the molecule require an expanded octet?

5+

which elements can have an expanded octet?

non-metals and metalloids in period 3 and below

is a period vertical or horizontal on the periodic table?

vertical

how many domains does a structure with a trigonal bipyramidal electron geometry have?

5

which electron geometry structure has a 90 & 120 bond angle?

trigonal bipyramidal

what electron geometry structure has 6 domains?

octahedral

what are the bond angles for a structure with octahedral electron geometry?

180 & 90 degrees

what does molecular geometry mainly have to deal with?

the placement of non-bonding electrons

what is the molecular geometry for this molecule? explain why?

bent ,due to the electrons on the central atom repelling the other elements away from it

what elements form an incomplete octet?

B, Al, and Be

what is an incomplete octet?

can have less than 8 electrons in compounds while remaining stable

electronegativity

measure of how much an atom attracts shared electrons towards itself in a covalent bond

what is a covalent bond?

two non-metals joining to share electrons

what’s a polar covalent bond

a covalent bond where the share of electrons is uneven between the two atoms

ionic bond

metal and non-metal. electrons are transferred

is C-H polar or non-polar?

always NP!

what is a hydrogen bond? when H is bonded to…, and it interacts with another… bond (look at what happens if it

O, N, or F

is the central atom the most or least electronegative atom? what is the exception?

the least electronegative, hydrogen is the exception because of the duet rule

why does dimethyl ether have a dipole dipole intermoelculer force acting upon it?

Because of the electrons, they repulse the C-O bonds, causing then to both point down rather than be on opposite sides of eachother. this causes a net down

(conversion factors) BULN

when you go from a big unit to a smaller one you get a little number

molality formula

m= n-solute / kg solvent

molarity formula

M = n-solute / L solution

mol fraction formula

X solvent = n-solvent / n-total (same for solute)

mass percent formula

mass-solute / mass-solution x 100

density formula

D= mass/ volume

ppm formula

(mass solute/ mass solution) x 10^6