Chemistry Review #2 - Test 2
A lewis structure for BrO3- is shown below without formal charge minimization. Correct with minimal formal charges.
** **O** - *BR* = **O** + another double bonded O with 4 electrons (Oxygen with 6 electrons and single bond, Br central with lone pair with two double bonded oxygen's with 4 electrons).
H2SO3 below is incorrect. Correct with minimized formal charges.
0=6, H=1, S=6. 6x2=12+1(2)+6=26 S has a LONE PAIR. S with lone pair connected two a double bonded Oxygen with 2 lone pairs, and two single-bonded Oxygens with two lone pairs each connected to a Hydrogen.
A vitamin's chemical formula has one cobalt. What is the molar mass if it contains 4.34% cobalt?
1,360cmpd/molcmpd x = 58.90gx100/4.34 x = 1357.14 > 1360.
What is the bond order of F2?
1/2(10-8) =1 Bond order = 1
A sample of hydrate of copper (II) sulfate is found to contain 36.08% water by mass. What is the formula of the hydrate?
100-36.08=63.92% 36.08% / 18.02 = 2.002molH2O 63.92% g CuSOv4 / 159.61 g = 0.4005molCuSO4 CuSO4 x 5 H2O
Which of the following contains the MOST moles of atoms?
1g of Helium (because it has the smallest mass on the Table compared to other options)
Hydronium ion shown below. H3O+. Predict if bonding angle A will be =, >, or < than the ideal bonding angle according to VSEPR model.
Angle A in Hydronium (H3O+) is LESS THAN VSEPR model.
What of the following is a nonpolar covalent bond?
Any molecule bonding to itself. ex. F-F
Correct formula for barium phosphate
Ba3(PO4)2
Draw lewis structure of AsF5. Determine ideal bonding angle of central atom. A 90 B 60 C 90/120 D 45 E 120
C 90/120 AsF5 has 90* and 120* angles. One As surrounded by 5x F's with each three lone pairs.
What is the molecular formula of a compound /w an empirical formula of CH and a molar mass of 78.1g/mol?
C6H6
Draw lewis for CH3F, determine if polar.
CH3F is a POLAR substance. F has three lone pairs, with Carbon in the middle and three hydrogens.
Calcium sulfate dihydrate
CaSO4 * 2H2O
Provide correct IUPAC name for CaBr2.
Calcium bromide
Draw lewis structure of ClF3, chlorine trifluoride, /w minimized formal charges. Determine electron domain and molecular geometry.
Cl with two lone pairs, single bonded to three F's with 3 lone pairs. Trigonal bipyramidal, T-Shaped
Write chemical formula for cesium carbonate?
Cs2CO3
Draw lewis structure for XeF2, determine ideal bonding angle(s) of the central atom.
F - Xe - F -> 6 electrons each atom, 3 lone pairs each. 180 degree bond angle for XeF2.
An iron containing compound is 20.1% Fe, 11.5% S, 63.3% O, 5.1% H. What is empirical formula for the compound?
FeSO 11 H 14 Assuming there is 100g in the sample, calculate the amount of each element to find the ratio between one element to another.
Draw the lewis structure for HCN, determine electron domain and molecular geometries.
Linear / Linear H - C = N : -
Draw the lewis structure of Br3-, determine electron domain and molecular geometry.
Linear structure, Trigonal Bipyramidal. Br - Br - Br (each with three lone pairs)
IUPAC name for Mg3(PO4)2
Magnesium Phosphate
Draw lewis structure of NO< chose formal charges. Write the elements in the order given.
N = O N has one single valence electron and double bond with Oxygen. One pair underneath nitrogen and one under Oxygen. N = 0, 0 = 0.
determine the number of valence electrons in nitrate (NO3-) and draw lewis.
NO3- has 24 total valence electrons. N with a double bonded oxygen with two lone pairs attached to O. Two single bonded oxygens with three lone pairs attached to N.
Determine the # of valence electrons in POCL3 aka trichloro phosphate. Draw Lewis using octet rule.
P surrounded by 3x Cl with 6 electrons in each Cl. One Oxygen surrounding P has 6 electrons as well.
Draw the lewis structure of PH3, determine electron domain and molecular geometry.
P with a lone pair, single-bonded to Hydrogen.
Draw lewis structure for SO2 (following octet rule). Determine # of nonbonding electron pairs on central atom.
S with a double bonded oxygen and a single bonded oxygen. S has one lone pair, double oxygen has two lone pairs, single oxygen has three lone pairs.
Lewis structure of a Phosphate (PO4^3-) Show minimized formal charges, determine hybridization of central atom.
Sp3 Hybridization Tetrahedral P surrounded by 4 O's, three full oxygens (6) have a -1 charge. Bottom hydrogen has a double bond and (4) electrons.
Draw the lewis strcuture of acetaldehyde (CH3CHO). choose the appropriate molecular geometry of the two central atoms.
Tetrahedral/Trigonal Planar Two C's linked together, one with 3 H's single bonded to it, one with a double bonded Oxygen with two lone pairs and one single bonded Hydrogen.
Draw the Lewis structure of HCLO3, follow octet rule. Find molecular geometry for the two central atoms.
Trigonal Pyramid / Bent (109.5*) 2x Full O's, 2 lone pair O, one pair on Cl.
Ethanol CH3CH2OH (grain alcohol). Draw lewis structure and determine hybridization of atom of Oxygen.
Two central carbons. One surrounded by 3 hydrogens, one surrounded by two hydrogens and an Oxygen with two lone pairs. Ethanol CH3CH2OH is a Tetrahedral (Sp3)
Draw lewis structure for IF5, determine electron domain and molecular geometry.
Octahedral / Square Pyramidal I with a lone pair, surrounded by 5 F's with 3 lone pairs.
Draw Lewis structure of SF6, determine appropriate # of valence electrons on central atom.
One central S surrounded by six F, each with three lone pairs.
