Assignment #4 from Chemistry CD ROM
Concentration, molar mass and reactions

The following problems are very similar to Chapter 3: Problems 1-4, 6-14, 23-29 and 51 from the CD ROM. Check out how those ones are solved and also Chapter 3: sections 1, 2, 4, 5, 6 of the Study Guide and the worked examples. The numbers to be used in questions 2 and 3 are your day of birth. So if your birthday is August 21, you will use 21 moles and 21 grams in questions 2 and 3 respectively. Similarly, for questions that say "(your body mass in kg)" you should use that number. E-mail me and/or the class e-mail list if you are having trouble figuring out how to do any of this. (The links above will only work if you insert your CD-ROM.)

Questions 8 and 9 are for those working to get a 100%. If you do questions 1 to 7 only you will receive up to 90%.


1. What is the molar mass of each of the following?
A) MgCl2 B) HI C) Ba(C2H3O2)2
2. Assume you have (fill in your day of birth here) moles of each of the substances in question 1. How many grams will you have for each?
3. Assume you have (fill in your day of birth here) g of each of the substances in question 1. How many moles will you have for each? For compound C) how many of each type of ATOM will you have?

4. What is the mass, in grams, of one lead atom?

5. What is the molarity of each of the following?
A) 200. mL of solution with (your body mass in kg) moles of NaCl in it
B) 150. mL with (your body mass in kg) moles of KNO3 in it
C) 1.25 L with (your body mass in kg) moles of KBr in it
6. Determine the mass of the substance needed to prepare (your body mass in kg) milliliters of the following.
A) .450 M MgCl2
B) .825 M NaNO3
C) .065 M CuSO4
7. Balance the following equations and name their reaction type (for A, B, D).
A) NaNO3 + Ba3(PO4)2 => Na3PO4+ Ba(NO3)2
B) Fe2O3+ HF => FeF3+ H2O
C) O2+ K2S => K2O + SO2
D) As + O2 => As2O3
E) 1-Nonyne (C9H16) undergoes combustion.
8. Marble statues and buildings deteriorate because of the reaction (check to see if it is balanced)
H2SO3 + CaCO3 => H2O + CO2 + CaSO3.
How many grams of marble (CaCO3) will react with (your body mass) kg of pure H2SO3? If the H2SO3 were in 1.00 x 104 L of rain water, what is the molarity of the solution?

9. Using the balanced equations from problem 7D), assume you have (your day of birth) moles of each reactant.

i.  What are the limiting and excess reactants?
ii.  What is the theoretical yield?
iii.  If the percent yield is 40% find the actual yield in grams.
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