ch. 11 & 3  IMF & stoichiometry                     ap chem

For problems involving calculations, show the relevant equation (or formula and conversion factor(s)), show your work in an organized manner, put the proper units in your calculations / answer, and have the proper number of significant figures in your answer.  [70 points]

1.  Which compound,

            CH4 , CH3 CH3 , or CH3 CH2 CH3

has the highest boiling point ?  highest vapor pressure ?  Justify your answer; include the term, polarizability.   [10 points]


2.  Identify the type of IMF in each molecule

            CH3 Cl;  CH4 ;  CCl4

include the basis of your choice.   [10 points]

 

3.  Balance the following chemical reactions using the lowest ratio of coefficients; include a “1” as appropriate; need not show work.  [15 points]

a.  an aqueous solution of calcium chloride reacts with another aqueous solution of sodium phosphate to form solid calcium phosphate and an aqueous solution of sodium chloride.

b.  ___  Al  +  ___  H2 SO4    -->  Al2 (SO4 )3   +  ___  H2  

c.   ___  Be2 C  +  ___  H2 O  -->  ___  CH4   +  ___  Be(OH)2

 

4.   In regards the chemical reaction   [15 points]

            C2 H6   +  O2   -->  CO2   +  H2 O

a.  write the balanced chemical equation using the lowest ratio of coefficients.

b.  How many grams of water would be produced by mixing 10.0 gram of C2 H6 and 30.0 grams of O2 ?  [hint:  identify the limiting reactant]


5.   Rationalize the relative boiling point of the following chemicals; include “what does dipole moment measure ?” in your answer.  [10 points]

 

chemical formula

molar mass (g / mol)

dipole moment (D)

boiling point (K)

CH3 CH2 CH3

44

0.1

231

CH3 OCH3

46

1.3

248

CH3 Cl

50

1.9

249

CH3 CHO  (aldehyde)

44

2.7

294

CH3 CN

41

3.9

355

6.  old topic:  What are five of  the possible 4 quantum numbers (n, l, ml , ms ) of  a __  atomic orbital ?  [10 points]

a.  3p

b.  4d