CHEM105 101
Math
Electrons
New Material
Miscellaneous
100
How many significant figures should the answer of the following have?
8279.21/27.4
3 sig figs
100
How much 0.05 HCl solution, in L, can be made by dilution 250 mL of 10 M HCl?
50 L 0.05 HCl
100
What element does the following electron configuration represent? How many valence electrons does the element have?
1s22s22p63s23p64s23d104p3
As, 5 valence electrons
100
Which of the following is NOT a common exception to the octet rule?
a. B
b. S
c. Be
d. N
e. P
d. N
100
Name the strong acids.
HI, HCl, HBr, HNO3, HClO4, H2SO4
200
How many neutrons does fluorine, F, have?
10 neutrons
200
Calculate the enthalpy of the following reaction using the reactions below: CS2(ℓ) + 3O2(g) --> CO2(g) + 2SO2(g)
C(s) + O2(g) --> CO2(g) ΔH = −393.5 kJ/mol
S(s) + O2(g) ---> SO2(g) ΔH = −296.8 kJ/mol
C(s) + 2S(s) ---> CS2(ℓ) ΔH = +87.9 kJ/mol
-1075 kJ/mol
200
Which of the following would have the largest ionization energy, electron affinity, and smallest atomic size?
a. S
b. He
c. Te
d. Al
a. S
200
Draw the resonance structure of CHO2. You MUST include all lone pairs and formal charges to receive points.
(Jada will draw one on the board)
On board
200
Which of the following arrows represents an emission with the largest wavelength?
II
300
Which of the following is NOT a mixture?
a. Tap water
b. Sugar
c. Bronze
d. Coffee
b. Sugar, compound
300
What is the enthalpy of formation of the following reaction? Is this reaction endothermic or exothermic?
3 KClO4 (s) + 8 Al (s) --> 3KCl (s) + 4Al2O3 (s)
ΔHf values: KClO4 = -432.8 kJ/mole, KCl(s)= -436.5 kJ/mole, Al2O3(s)= -1675.7 kJ/mole
-6714 kJ/mole, exothermic
300
Identify what is being oxidized and reduced in this redox reaction by assigning oxidation numbers to the atoms.
2Rb + MgCl2 → 2RbCl + Mg
oxidized: Rb; reduced: Mg
300
Which of the following is polar?
a. CO2
b. SO2
c. Zn2+
d. CF4
b. SO2
300
Which of the following would have the largest atomic radius?
a. Te2-
b. I-
c. Cs+
d. Ba2+
a. Te2-
400
Name the following compounds (100 for each you get right):
NaF
ICl3
N2O3
SnCl4
NaF: sodium fluoride
ICl3: iodine trichloride
N2O3: dinitrogen trioxide
SnCl4: tin (IV) chloride
400
Calculate the specific heat capacity of a new alloy if a 15.4 g sample absorbs 393 J when it is heated from 0.0°C to 37.6°C.
c = 0.679 J/g*K
400
Identify how many electrons could have the following quantum numbers: n=3, l=2
10 electrons
400
What is the molecular geometry of BH2-? What is the electron-pair geometry?
Molecular: trigonal planar
Electron-pair: bent
400
Classify the following reaction:
Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2 H₂O
Acid-base reaction
500
Write the net ionic equation for the following reaction:
Ca(OH)2 (aq) + FeCl3 (aq) -->
Hint: Write your products, then balance. Then write your total ionic equation, and cancel out to get NIE
Fe3+ (aq) + 3 OH- (aq) --> Fe(OH)3 (s)
500
A compound with a molecular mass of 60.0 g/mol is found to contain 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen. What is the molecular formula?
C2H4O2
500
What is the correct Lewis structure of NH2OH? (Yes, you have to come to the board and draw this to get the points)
On board
500
What is the hybridization of NO2-?
sp2
500
85.4 g of chlorine (70.91 g/mol) reacts completely according to the following reaction:
P4 (s) + 6 Cl2 (g) --> 4 PCl3 (l)
If 104 g of phosphorus trichloride (137.3 g/mol) is produced, what is the percent yield for this reaction?
94.5%