Problems Flashcards
(24 cards)
another binary compound of nitrogen and oxygen is 46.6% nitrogen and 53.4% oxygen and has a molecular weight of 29.87 g/mol.
N: 46.6/ 14.00674=3.33 O: 53.4/15.9994=3.31 divide by smallest 3.31 N=1, O=1 NO emp. (14.00674+15.9994)x=29.87 Solve: x=.995 or 1 NO molec.
a) simplest whole number ratio of atoms present.
b) empirical formula mass
c) multiplier
d) molecular formula
Multiplier x coefficients of empirical formula
No solution.
A compound is 27.3% carbon and 72.7% oxygen. It is determined to have a molecular weight of 43.90% g/mol.
C: 27.3/ 12.011=2.27 O: 72.7/ 15.9994= 4.54 divide by smallest 2.27 C=1, O=2 CO2 emp. (12.011 + 2 x 15.9994)x=43.90g/mol Solve: x=.998 or 1 CO2 molec.
Oxidation numbers:
Se: in H2SeO3 = H2: 1 Se O3: -2 2x1+Se+3x-2=0 2+Se+(-6)=0 Se-4=0 Se=4
I in NaIO4
1+I+4x-2=0
1+I-8=0
I-7=0
I=7
S in SO3 to the -2
O=-2
S+3x-2=-2
S-6=-2
S=4
N2O5
2N+5x-2=0 O=-2
2N-10=0
minus 10 Nitrogen(v) oxide
2N=10 Dinitrogen Pentoxide
divide
N=5
P3N5
P=5 O=-3 Opposite to each side
Phosphorus(v) oxide
Triphosphorus oxide
PtCl2
Pt=2 Cl=-1 Plantinum(II) Chloride
Plantinum Dichloride
P4O10
P=5 O=-2 If divisible by two do it
phosphorus(v) oxide
Tetraphosphorus Decoxide
Conversion Factor
1 mole x = formula mass g x = 6.023E23 molecules/formula unit
CF
1 mole x formula mass g x
———— —————
formula mass g x 1 mole x
CF
1 mole x 6.023E23 molecules x
- 023E23 molecules x 1 mole x
CF
Formula mass g x 6.023E23 molecules x
- 023E23 molecules x formula mass g x
Formula mass and mole conversions
for 160g of SO2, how many moles
32.066+2x15.9994=64.06g/mol
160g SO2 1 mol SO2
------------------------------------------ = 2.50 mol SO2
64.06g SO1Ammonium Hydroxide
NH+4OH- NH4OH
Zinc Oxide
Zn+2 HS- Zn(HS)2
Cuprous Thiosulfate
Cu- S2 O3 -2 Cu2S2O3
PbCr2O7
Lead Dichromate
H3PO4
Hydrogen Phosphate
Percent composition
NaHCO3 22.99+1.00794+12.011+3x15.9994=84.01g/mol
- 99/84.01 x100=27.37%Na
- 00794/84.01 x100=1.20%H
- 011/84.01 x100=14.30% C
3x15. 9994/84.01 x100=57.14%O
Formula Mass
H3PO4
3x1.00794+30.973762+4x15.9994=98.00g/mol
Formula Mass
Fe(C2H3O2)3
55.847+6x12.011+9x1.00794+6x15.9994=232.98g/mol
Electron Configuration
Silicon a) [Ne] 3s2 2P2 b)1s2 2s2 2p6 3s2 p2 11 11 11 11 11 11 1 1 -- -- -- -- -- -- -- -- 1s 2s 2p 3s 3p
