Exam 1
Write the following in 4 significant figures:
1. 375.6523
2. 5000
3. 29.999998
4. 4.000574*10^6
1. 375.7
2. 5000.
3. 30.00
4. 4.001*10^6
Calculate the wavelength (in nm) of electromagnetic radiation that has a frequency of 9.87x1015Hz?
30.4nm
Place the following subshells in the order of increasing energy: 3s, 4s, 2p, 3d, 4p, 5s.
2p, 3s, 4s, 3d, 4p, 5s
Write the molecular, ionic, and net ionic equation for the reaction between hydrochloric acid and lithium hydroxide.
Molecular: HCl(aq)+LiOH(aq)--> H20(l)+LiCl(aq)
Ionic: H+(aq)+Cl-(aq)+Li+(aq)+OH-(aq)-->H20(l)+Li+(aq)+Cl-(aq)
Net ionic: H+(aq)+OH-(aq)-->H20(l)
Explain the difference between a dilution and titration in your own words.
Dilution=make 1 stock; less concentrated
Titration= mix 2 solutions together, find moles or liters of unknown.
A rubber ball in submerged into a graduated cylinder with a volume of 12.0mL of water. After the addition of the rubber ball, the volume reads 122.5mL. If the mass of the rubber ball is 3.54 grams. What is the density of the ball in g/mL?
1.4g/mL
A single photon has an energy of 4.25x10-16J. What is the wavelength of this radiation in nm?
0.468nm
Write the full and simplified electron configuration for each ion below. Which noble gas isoelectronic?
O2-, Br-, and Sr2+
O2-: 1s22s22p6or [Ne]
Br-: 1s22s22p63s23p64s23d104p6 or [Kr]
Sr2+: (same as Br-)
Br-and Sr2+ are isoelectronic
Redox reaction: identify which reactant is oxidized and which reactant is reduced.
Zn(s)+CuSO4(aq)-->ZnSO4(aq)+Cu(s)
Zinc lost e---> oxidation
Cooper gained e--->reduced
Calculate the overall change in internal energy, in joules, for a reaction that absorbs 188J of heat and does 141J of work on its surroundings. Is this reaction endothermic or exothermic?
DeltaU=188J-141J=47J (endothermic)
What are atoms made of? And what do you know about them?
Protons, neutrons, and electrons
Protons have a positive charge, in nucleus contribute to atomic mass, ~1amu
Neutrons are neutral with no charge to contribute to atomic mass, ~1 amu
Electrons have a negative charge, outside of the nucleus, takes up more volume and very small (negligible) mass.
True or false
1. Electrons can move to a higher energy state without the addition of energy
2. Absorption is when an electron goes from a lower energy state to a higher energy state.
3. Emission is when an electron goes from a lower energy state to a higher energy state.
4. As energy states increase, they become closer together.
1. F
2. T
3. F
4. T
Write the missing name and formula:
SO2
P5Cl10
P4O9
Selenium heptachloride
Carbon tetrahydride
Nitrogen trihydride
1. Sulfur dioxide
2. Pentaphosphorus decachloride
3. tetraphosphorus nonaoxide
4. SeCl7
5. CH4
6. NH3
Your experiment calls for 3.00L of a 0.500M calcium chloride solution. A 10.0M calcium chloride stock solution is available. How can you prepare your solution for your experiment?
Lc=0.150L
You find a penny in the snow and hold it in your hand. How much heat is absorbed by the penny as it warms from the temperature of the snow, which is -8.0 degrees Celsius, to the temperature of your body, 37.0 degrees Celsius? You may assume that the penny is solid copper, which has a specific heat capacity of 0.385 J/g*C and a mass of 3.10g.
q=sm delta T
q=53.7J
Oxygen is the most abundance element in both Earth's crust and the human body. Oxygen has three stable isotopes, listed below. Calculate the average atomic mass of oxygen using the relative abundances.
16O=15.9949 amu and 99.757%
17O=16.9991amu and 0.038%
18O=17.9992 amu and 0.205%
15.999 amu
(be careful with sigfigs, they might have one of more options that make you keep up with them)
List the possible values of n, l, ml, ms for a 2p orbital.
<2,1,-1,1/2>, <2,1,0,1/2>, <2,1,1,1/2>,<2,1,-1,-1/2>,<2,1,0,-1/2>, <2,1,1,-1/2>
Determine the empirical formula of a compound that is 56.95% copper, 14.37% sulfur, and 28.68% oxygen.
Cu2SO4 (Copper (l) Sulfate)
0.150 M barium hydroxide is titrated into 25.0mL of 0.100 M HCl. What volume of barium hydroxide is required to neutralize the acid? Begin by writing the balanced equation.
Ba(OH)2(aq)+2HCl(aq)-->2H20(l)+BaCl2
0.00833L of barium hydroxide
You combine 0.158g of Mg metal with enough aqueous HCL to make 100.0mL of solution in a calorimeter. The HCl is sufficiently concentrated so that the Mg completely reacts. The temperature of the solution rises from 25.6 C to 32.8 C as a result of the reaction. use 1.00g/mL as the density of the solution and soln=4.184J/g*C as the specific heat capacity of the solution. Report qrxn for the following reaction in kJ.
-3.0kJ and exothermic
Which of the following has a great mass: 173 atoms of gold or 7.3x10-22mole of silver?
7.9x10-20g of Ag
A photon has a wavelength of 133.4nm. Calculate the total energy, kJ, of a mole of these photons.
898 kJ/mol
What is the percent composition of each atom in Zinc Sulfate?
Zn: 40.51%
S: 19.86%
O: 39.63%
Calculate the molarity of total ions in 1.0M ammonium sulfate, 2.0M lithium hydroxide, and 3.0M carbon tetrahydride.
3.0 mol ions of SO4
2.0 mol ions of LiOH
CH4 is a nonelectrolyte so will not break into ions
Calculate deltaH for the reaction: N2O(l)+NO2(g)--> 3NO(g)
Use the following thermochemical equations.
2NO(g)+O2(g)-->2NO2(g) deltaH=-113.1kJ
N2(g)+O2(g)--> 2NO(g) deltaH=+182.6kJ
2N2O(l)--> 2N2(g)+O2(g) delta H=-184.7kJ
N2O(l)+NO2(g)-->3NO(g) deltaH=146.8kJ
(endothermic)