exam II

Question 1

what is the shape of TeF4

Answer 1

trigonal bipyramidal

Question 2

what is the molecular geometry of XeO3

Answer 2

trigonal pyramidal

Question 3

how do you find the formal charge of an atom?

Answer 3

of VE – # of bonds – # of Individual lone pairs

Question 4

how do you find the hybridization of an atom

Answer 4

count the number of bonds and lone pair GROUPS then count up to that number in spppddddd…

Question 5

how do you find the percent by mass

Answer 5

atomic mass 1 / atomic mass 2

Question 6

how do you find how many molecules are in something

Answer 6

g x (1 mol x/molar mass x) x 6.022x10^23

Question 7

how do you find the amount of grams produced

Answer 7

x mol (1 mol y / 1 mol x) (molar mass x / 1 mol y)

Question 8

how do you find the empirical formula

Answer 8

g of x/ molar mass of x; g of y / molar mass of y; divide by the smallest answer on both sides; multiply both sides by the same # to get a whole #.

Question 9

describe the difference between molecular and ionic.

Answer 9

molecular bonds are between two nonmetals, and ionic bonds are between a metal and a nonmetal.

Question 10

what are the semimetals

Answer 10

B, Si, Ge, As, Sb, Te, At

Question 11

NH4

Answer 11

ammonium

Question 12

Hg2^2+

Answer 12

mercury I

Question 13

C2H3O2^-

Answer 13

acetate

Question 14

CO3^2-

Answer 14

carbonate

Question 15

ClO3^-

Answer 15

chlorate

Question 16

CN^-

Answer 16

cyanide

Question 17

HCO3^-

Answer 17

hydrogen carbonate

Question 18

OH^-

Answer 18

hydroxide

Question 19

ClO^-

Answer 19

hypochlorite

Question 20

NO3^-

Answer 20

nitrate

Question 21

ClO4^-

Answer 21

perchlorate

Question 22

PO4^3-

Answer 22

phosphate

Question 23

SO4^2-

Answer 23

sulfate

Question 24

do nonmetals tend to lose or gain electrons?

Answer 24

gain

Question 25

what is the charge of a Na ion and why?

Answer 25

+1, because it lost an electron

Question 26

what makes Cl special?

Answer 26

it is a peripheral atom, meaning it can use the d orbital to bond, aka have more than 8 valance electrons/bonds

Question 27

how do you find the formal charge of an atom?

Answer 27

ve of neutral atom - # of bonds - # of nonbonding electrons

Question 28

what does one amu equal?

Answer 28

1.661 x 10^-24 g

Question 29

how do you find the mol of 3.08g of CO2

Answer 29

(3.08g)(1mol/44.01g)= .07 mol
CO2

Question 30

what are the angles of
AE2
AE3
AE4
AE5
AE6

Answer 30

linear
trigonal planar
tetrahedral
trigonal bipyramidal
octahedral

Question 31

what is a sigma bond

Answer 31

a single bond

Question 32

A naturally occurring sample of an element contains only two isotopes. The first isotope has a mass of 68.9255 amu and a natural abundance of 60.11%. The second isotope has a mass of 70.9247 amu. Find the atomic mass of the element.

Answer 32

(68.9255+70.9247)/2= 69.93

Question 33

Determine the number of atoms in 1.85 mL of mercury. (The density of mercury is 13.5 g/mL.)

Answer 33

1.85(13.5)= 24.975 x 6.022x10^23= 1.5x10^25

Question 34

A 20.0 g sample of an element contains 4.95  1023 atoms. Identify the element.

Answer 34

4.95x10^23(1 mol/6.022x10^23)= .822
20/.822= 24.33
Mg

Question 35

Determine the number of CH2Cl2 molecules in 25.0 g of CH2Cl2

Answer 35

25 x 6.022x10^23= 1.51x10^25 moles

Question 36

Which molecular geometry results when a central atom has five total electron groups (three bonding groups and two lone pairs)?

Answer 36

t shaped

Question 37

Determine the mass of potassium in 35.5 g KBr

Answer 37

35.5/119= .298x39.26= 11.7