Chemistry 111 Web Lectures Bradbury Home Page
Here are some mini lectures of problems similar to those done in class.
Read the problem, then click on the link to watch the solution. These lectures are performed in Windows Media Player and in Quick Time, so choose the format that works for you. Make sure you watch on full screen. There is accompanying sound. If the computer you are working on has no speakers you can use headphones. Bring your own Walkman type headphones if you are using the Cerritos College computers. Some of the problems are done in more than one part due to disk space.
You may also want to review the Chemistry 110 Web lectures that apply to Chem. 111
Unit 1: Stoichiometry
Excess amount of HCl is added to a mixture of CaCO3 and K2CO3. The mixture reacted completely.
CaCO3 + HCl ŕ CaCl2 + H2O + CO2
K2CO3 + HCl ŕ 2 KCl + H2O + CO2
4.48 g CO2 and 3.57 g KCl are produced along with CaCl2 and H2O. What is the mass of the original mixture?
Solution Pt. 1 Solution Pt. 2 Solution Pt. 3 Solution Pt. 4
Transcript pt. 1 Transcript pt. 2 Transcript pt. 3 Transcript pt. 4
A compound has the formula BxH20O3. It contains 36.14 % by mass oxygen. What is X?
Solution Pt. 1 Solution Pt. 2 Solution Pt. 3 Solution Pt. 4 Solution Pt. 5
Transcript pt. 1 Transcript pt. 2 Transcript pt. 3 Transcript pt.4 Transcript pt. 5
The percent of aluminum in the compound Al2X3 is 18.56%. What is the molar mass of the element represented by X?
Transcript pt. 1 Transcript pt. 2
A sulfur containing compound is reacted to convert all of the sulfur into barium sulfate. A 8.19 mg sample of the compound produces 5.46 mg of barium sulfate.
What is the percent of the compound that is sulfur?
If there is one sulfur atom per molecule, what is the compound’s molar mass?
Solution Pt. 1 Solution Pt. 2 Solution Pt. 3 Solution Pt. 4
Transcript pt. 1 Transcript pt. 2 Transcript pt. 3 Transcript pt. 4
An alloy of Co, Rh and Mn are in the ratio of 2 to 5 to 2 respectively. What is the mass of a sample of this alloy that contains 8.75x 10 21 atoms?
A mixture of cobalt (II) oxide and cobalt (III) oxide contains 32.50 % by mass cobalt (II) oxide. What is the total number of oxide ions in a122 g sample of the mixture?
Solution Pt. 1 Solution Pt. 2 Solution Pt. 3
A 3.750 g sample of the compound containing only C, H, and O is burned in a combustion analysis apparatus. The mass of CO2 produced is 10.05 g and the mass of H2O produced is 2.470 g. What is the empirical formula of the compound?
Pt. 1 Windows Media Pt. 1Quick Time
Pt. 2 Windows Media Pt. 2Quick Time
Pt. 3 Windows Media Pt. 3Quick Time
Pt. 4 Windows Media Pt. 4Quick Time
Unit 3: Solutions
What volume of a .500 M solution of NaCl (molar mass 58.45 g) would contain 35.21 g of the solute?
How many grams of sucrose (molar mass 342.22 g) would be needed to prepare 1505 ml of a 2.4 M solution?
What is the molarity of a 1.45 m sucrose (molar mass 342.22 g) solution that has a density of 1.10 g/ml?
Pt 1 WMP Pt 2 WMP Pt 3 WMP Pt 4 WMP
Net Ionic Equations
Write the molecular, total and net ionic equations for the following reaction: Aqueous sodium oxalate is added to hydrochloric acid.
Molecular equation WMP Total ionic equationWMP Net ionic equation WMP
Molecular equation QT Total ionic equation QT Net ionic equation QT
Write the molecular, total and net ionic equations for the following reaction: aqueous solutions of copper (I) chloride and sodium nitrate are mixed.
Molecular and Total ionic equations WMP Net ionic equation WMP
Molecular and Total ionic equations QT Net ionic equation QT
Write the molecular, total and net ionic equations for the following reaction: aqueous solutions of sodium hydroxide and zinc nitrate are mixed.
Molecular equation WMP Total ionic equation WMP Net ionic equationWMP
Molecular equation QT Total ionic equation QT Net ionic equation QT
How many grams of precipitate are formed when 25 g of potassium hydroxide (molar mass 56.11) are added to 250.0 ml of 1.50 M CuSO4(molar mass 159.6)?
Net Ionic Equations
Write the molecular, total and net ionic equations for the following reaction: Aqueous sodium oxalate is added to hydrochloric acid.
Molecular equation WMP Total ionic equationWMP Net ionic equation WMP
Molecular equation QT Total ionic equation QT Net ionic equation QT
Write the molecular, total and net ionic equations for the following reaction: aqueous solutions of copper (I) chloride and sodium nitrate are mixed.
Molecular and Total ionic equations WMP Net ionic equation WMP
Molecular and Total ionic equations QT Net ionic equation QT
Write the molecular, total and net ionic equations for the following reaction: aqueous solutions of sodium hydroxide and zinc nitrate are mixed.
Molecular equation WMP Total ionic equation WMP Net ionic equationWMP
Molecular equation QT Total ionic equation QT Net ionic equation QT
How many grams of precipitate are formed when 25 g of potassium hydroxide (molar mass 56.11) are added to 250.0 ml of 1.50 M CuSO4(molar mass 159.6)?
What is the normal boiling point of a 2.70 M solution of KBr that has a density of 1.80 g/ml? (Kb for water is 0.512 oC/molal)
Boiling Point Part 1 Boiling Point Part 2
A solution consists of 3.88 g of benzene and 2.45 g of toluene C6H5CH3 . The vapor pressure of pure benzene at 20oC is 75 mm Hg and that of toluene at the same temperature is 22 mm Hg. Assume that Raoult's law works for each part of the mixture. Calculate the mole fraction of benzene in the vapor. (Molar mass of benzene is 78.0 g/mole and molar mass of toluene is 92.0 g/mol.) (Note: in the video the stated vapor pressures of benzene and toluene in the given problem are incorrect. In the solution they are correct. They are also correct in the stated problem above.)
Vapor Pressure Part 1 Vapor Pressure Part 2
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