Chapters 1-2: Atomic Structure and Formula Calculations
Which electronic transition in a hydrogen atom is association with the largest emission of energy?
a) n = 2 to n = 1
b) n = 2 to n = 3
c) n = 2 to n = 4
d) n = 3 to n = 2
a) n = 2 to n = 1
What is the molarity of a solution prepared by dissolving 12.0 g NaCl in 300.0 mL water?
0.683 M
How much heat (in J) is required to raise 75.0 g of water from 25 C to 55 C? (c=4.184 J/gC)
q = m*c*deltaT
9,414 J
What is the molecular geometry of CO32-?
a. bent
b. T-shaped
c. trigonal bipyramidal
d. trigonal planar
d. trigonal planar
A 10.0 L sample of an ideal gas at 25.0 C is heated at a constant pressure until the volume has doubled. What is the final temperature of the gas?
323 C
The formula for sodium dihydrogen phosphate is NaH2PO4
What is the formula of strontium dihydrogen phosphate?
Sr(H2PO4)2
Which molecular equation would give this net ionic equation: H+(aq) + OH-(aq) --> H2O(l)
a. H2SO4(aq) + 2NH3(aq) --> (NH4)2SO4(aq)
b. HCN(aq) + KOH --> H2O(l) + KCN(aq)
c. 2HClO4(aq) + Ba(OH)2(aq) --> 2H2O(l) + Ba(ClO4)2(aq)
c. 2HClO4(aq) + Ba(OH)2(aq) --> 2H2O(l) + Ba(ClO4)2(aq)
What is the enthalpy of formation of hydrazine, N2H4(l)?
3N2H4(l) --> 4NH3(g) + N2(g) detlaH = -336 kJ/mol
NH3 enthalpy of formation: -46.3 kJ/mol
50.3 kJ/mol
How many lone pairs of electrons are on the central atom of ClF3?
2 lone pairs
A 14.0 g sample of N2(g) occupies what volume at 0 C and 1.00 atm?
a. 5.60 L
b. 11.2 L
c. 14.0 L
d. 22.4 L
b. 11.2 L
What is the percent by mass of oxygen in Ca(NO3)2?
58.5%
A 2.32 g sample of Na2SO4*nH2O yields 1.42 g Na2SO4 upon heating.
Na2SO4*nH2O --> Na2SO4 + nH2O
What is the value of n?
n=5
What is the frequency of light with a wavelength of 480 nm?
a. 1.60x10-6 s-1
b. 6.25x105 s-1
c. 6.25x1014 s-1
d. 1.44x1020 s-1
c. 6.25x1014 s-1
Which species contains three sigma bonds and one pi bond?
a. PF3
b. NH4+
c. CO32-
c. CO32-
What volume (in L) of CO2(g), measured at 0.993 atm and 28 C, must react in order to completely consume 59.0 g of Al2O3(s)?
Al2O3(s) + 3CO2(g) --> Al2(CO3)3(s)
MM of Al2O3 = 101.96 g/mol
43.3 L
What is the empirical formula of a compound of carbon, hydrogen, and oxygen that contains 51.56% carbon and 14.09% hydrogen by mass?
C4H13O2
How many grams of NaOH are required to neutralize 50.0 mL of 0.100 M H2SO4?
0.4 g NaOH
H2SO4 + 2NaOH --> Na2SO4 + 2H2O
Which atom has the largest atomic radius?
a. K
b. Rb
c. I
d. Sn
Rb
Which of the molecules listed have an sp3 hybridized central atom?
I. PCl3 II. COCl2 III. SF4
a. I only
b. I and III only
c. II and III only
d. I, II, and III
a. I only (PCl3)
Which pair of compounds will form hydrogen bonds with one another?
a. CH4 and H2O
b. CH4 and NH3
c. HF and CH4
d. H2O and NH3
d. H2O and NH3
For each compound, classify as ionic, covalent, or an acid. Name the compound
a. CCl4
b. H2PO4
c. K3P
d. HgBr2
e. H2S
a. covalent, carbon tetrachloride
b. acid, phosphoric acid
c. ionic, potassium phosphide
d. mercury (II) bromide
e. (binary) acid, hydrosulfuric acid
What amount of the excess reagent remains when 0.500 mol Li reacts with 0.350 mol N2?
a) 0.0833 mol N2
b) 0.267 mol N2
c) 0.150 mol Li
d) 0.417 mol Li
b) 0.267 mol N2
Given the thermochemical data (on board) what is the deltaHrxn for:
CO(g) + 1/2O2(g) --> CO2(g)
C(s) + O2(g) --> CO2(g) deltaH = -394 kJ/mol
2C(s) + O2(g) --> 2CO(g) deltaH = -221 kJ/mol
-284 kJ/mol
Which species has a trigonal planar geometry?
a. ClF3
b. NCl3
c. CO3-2
d. I3-1
c. CO3-2
Arrange LiF, HCl, HF, and F2 in order of increasing boiling point.
a. F2 < HF < HCl < LiF
b. F2 < HCl < HF < LiF
c. F2 < HCl < LiF < HF
d. HF < LiF < HCl < F2
b. F2 < HCl < HF < LiF