Moles
How many moles of zinc nitrate are present in 37.6 mL of a 0.915 M solution?
0.0344 moles
What is the oxidation number of chromium in Cr2O72-
6+
A hot air balloon is floating in earth's atmosphere with a pressure of 0.846 atm and temperature of 42.3 oC. In order to return to the earth's surface, the balloons volume of air decreases from 2.67 x 103 L to 2.16 x 103 L. If the new atmospheric pressure is 758 mmHg, what is the final temperature (in Celsius) of the balloon?
27.7 oC
Calculate the energy of a light emitted by a photon with a wavelength of 706 nanometers.
2.82 x 10-19 J
What is the bond angle between Nitrogen and Hydrogen in NH3?
107o
How many moles of chlorine are present in 98.5 grams of magnesium chloride?
2.07 moles
What precipitate results when FeCl2 (aq) is reacted with AgC2H3O2 (aq)?
AgCl (s)
An unknown gas moves with a speed of 513 m/s at a temperature of 27.2 oC. What is the molar mass of the gas?
28.5 g/mol
Write the shorthand electron configuration of zirconium (Zr) and identify how many valence and core electrons zirconium has.
[Kr]5s24d2
Core electrons = 36
Valence electrons = 4
Is SeF4 a polar or non-polar molecule?
Polar
Rubidium has two isotopes, one has a mass of 85 amu and the other has a mass of 87 amu. If the atomic mass of rubidium on the periodic table is 85.468, what is the percent abundance of each isotope?
Rb-85 = 76.6%
Rb-87 = 23.4%
Given the following balanced chemical reaction:
H2S + Cl2 → S + 2HCl
Identify which element is being oxidized and which element is the oxidizing agent.
Sulfur is being oxidized
Chlorine is the oxidizing agent
A sample of an unknown gas has a density of 0.72 g/L at 221 K and under a pressure of 781 mmHg. What is the density of this gas at STP?
0.57 g/L
Draw a 4p orbital (including charges) and list the following:
n =
l =
ml =
angular nodes =
radial nodes =
n = 4
l = 1
ml = -1, 0, 1
angular nodes = 1
radial nodes = 2
How many lone pairs, sigma bonds, and pi bonds are present in SO42-?
Lone pairs = 10
Sigma bonds = 4
Pi bonds = 2
Salicylic acid has a composition of 60.78% carbon, 4.38% hydrogen, and the rest is oxygen. Given that its molar mass is 138.121 g/mol, what is the empirical and molecular formula of this organic acid?
Empirical = Molecular = C7H6O3
In a reaction between calcium hydroxide and hydrobromic acid, it takes 49.9 mL of 0.543 M calcium hydroxide to neutralize 17.6 mL of hydrobromic acid. What is the concentration of the acid?
3.08 M
A reaction between hydrochloric acid and aluminum produces hydrogen gas. This hydrogen gas is collected over water at 25 oC and a total pressure of 759 torr. If the volume of the hydrogen gas is 355 mL, then how many moles of hydrogen gas were produced? (Note the vapor pressure of water at 25 oC is 23.8 torr)
0.014 moles
Write the full electron configuration of V3+.
1s22s22p63s23p63d2
Show all resonance structures of HCO2-
Great Drawing!
Given the following unbalanced chemical reaction:
C2H6 + O2 → CO2 + H2O
If 216.2 grams of ethane gas are reacted with excess oxygen, how many grams of carbon dioxide are produced?
632.9 grams of CO2
Given the following reaction:
sodium carbonate (aq) + hydrochloric acid (aq) → sodium chloride (aq) + dihydrogen monoxide (l) + carbon dioxide (g)
If 4.32 grams of sodium carbonate react with 8.92 grams of hydrochloric acid, what is the limiting reagent?
Na2CO3
Using Van der Waals equation, calculate the temperature of 14.2 moles of helium in a 17.4 L container with a pressure of 55.0 atm. (a = 0.0341 and b = 0.0237)
806 K
Write the full electron configuration of copper, then draw the largest orbital it occupies, showing all nodes and charges. Finally, draw the radial distribution graph of this orbital.
1s22s22p63s23p64s23d104p65s14d10
4d orbital drawing
Draw the Lewis structure for XeCl3-. What is the electron geometry, molecular geometry, and hybridization of this compound?
Electron geometry = Octahedral
Molecular geometry = T-shaped
Hybridization = sp3d2