Stoich
What is the volume of 25 g of iodine (density = 4.93 g/cm^3)?
5.07 mL
Identify this reaction:
Ca + 2HCl --> CaCl2 + H2
Identify compound that is reduced, oxidized, reducing agent and oxidizing agent.
Single replacement
H is reduced (+1 --> 0)
Cl- does not change
Ca is oxidized (0 --> 2+)
H is the oxidizing agent
Ca is the reducing agent
How many kJ of heat are needed to completely vaporize 50.0g of water at 100°C?
The heat of vaporization of water is 2260 J/g.
113 kJ
Differentiate between the shells, subshells, and orbitals of an atom.
shell: set of orbitals in the same energy level
subshell: set of orbitals in the same energy level and same shape (s, p, d, or f)
orbital: can hold up to 2 electrons
Draw AlCl4-.
What is the electron geometry?
tetrahedral
Find the number of moles and mass of Chlorine (Cl2) required to react with 10.0 g of sodium metal, Na, to produce NaCl. Write a balanced equation.
2 Na + Cl2 --> 2NaCl
0.217 mol Cl2
15.43 g Cl2
A compound is found to contain 26.56% potassium, 35.41% chromium, and the remainder oxygen. Find the empirical formula.
K2Cr2O7
How much heat energy is obtained when 1 kg of ethane gas, C2H6, is burned in oxygen: 2C2H6 (g) + 7O2 (g) --> 4CO2 (g) + 6H2O (l) with delta H = -3120 kJ.
-51, 879 kJ
Given:
P = 1.01 atm
V= ?
n = 0.00831 mol
T = 25 deg C
0.20 L
Draw SF6.
What is the electron and molecular geometry?
octahedral, octahedral
Automotive air bags inflate when a sample of sodium azide NaN3 is rapidly decomposed. (2 NaN3 --> 2 Na + 3 N2)
What mass of sodium azide is required to produce 73.6 L of N2 with a density of 1.25 g/L?
142 g NaN3
Balance this equation: Mg(NO3)2 (aq) + Na2CrO4 (aq) --> MgCrO4 (s) + NaNO3 (aq)
Find ionic and net ionic eqn.
Mg(NO3)2 (aq) + Na2CrO4 (aq) --> MgCrO4 (s) + 2NaNO3 (aq)
A 360-g piece of rebar is dropped into 425 mL of water at 24.0 °C. The final temperature of the water was measured as 42.7 °C. Calculate the initial temperature of the piece of rebar. The specific heat of steel is 0.449 J/gC and the specific heat of water is 4.184 J/gC.
Ti = 248 degrees Celsius
Write the electron configuration of Ce.
[Xe]6s24f15d1
Determine the formal charges for (see drawing)
NCS- CNS- CSN-
Which is the best conformation?
NCS- : -1 0 0 = -1
CNS- : -2 +1 0 = -1
CSN- : -2 +2 -1 = -1
NCS- is the favored arrangement since it has the lowest number of atoms with nonzero formal charges.
If 10.0 mL of 0.300 M KOH are required to neutralize 30.0 mL of HCl, what is the molarity of the HCl?
0.100 M HCl
Balance MnO4- + I- --> I2 + Mn2+ in acidic media.
10I- + 16H+ + 2MnO4- --> 5I2 + 2Mn2+ + 8H2O
Given this overall reaction: 2NO2(g) + Cl2(g) → 2NOCl(g) + O2(g), ΔH = ?
1) 2NO(g) + Cl2(g) → 2NOCl(g), ΔH = -76 kJ
2) 2NO(g) + O2(g) → 2NO2(g), ΔH = -114 kJ
Find delta H.
ΔH = +38 kJ
A sample of He gas occupies 2.65 L at 1.2 atm. What pressure would this sample exert in a 1.50 L container at the same temperature?
2.12 atm
Draw the resonance structures of the carbonate ion. What is the molecular geometry?
see drawing, trigonal planar
Given this reaction: C6H6 + Br2 --> C6H5Br + HBr
a. find the theoretical yield of C6H5Br if 42.1 g of C6H6 react with 73.0g of Br2. Which is the limiting reagent?
b. if the actual yield of C6H5Br is 63.6 g, what is the percent yield?
a. 71.6 g C6H5Br
b. 88.8%
A sample of a compound with a formula mass of 34.00 u consists of 0.44 g H and 6.92 g O. Find the molecular formula.
H2O2
1.000 g sample of octane (C8H18) is burned in a bomb calorimeter containing 1200 grams of water at an initial temperature of 25.00ºC. After the reaction, the final temperature of the water is 33.20ºC. The heat capacity of the calorimeter is 837 J/ºC. The specific heat of water is 4.184 J/g ºC. Calculate the heat of combustion of octane in kJ/mol.
-48.1kj
Identify the subshell in which electrons with the following quantum numbers are found:
1. 3d
2. 1s
3. 4f
Determine if the following have polar bonds and an overall dipole moment.
SF2
ICl3
BrCl4-
H3O+
PCl4-
SnCl3-
XeF4
SF2 - polar bonds, dipole moment
ICl3 - polar bonds, dipole moment
BrCl4- - polar bonds, no net dipole moment
H3O+ - polar bonds, dipole moment
PCl4- - polar bonds, dipole moment
SnCl3- - polar bonds, dipole moment
XeF4 - polar bonds, no net dipole moment