Name: _________________________________________
Date:____________________________
Optional Homework 4
1.) Compare the following systems and choose the member with the highest entropy in each pair: JUSTIFY
your choice (assume constant temperature unless indicated!)
a. 1 mole of SO2 (g) or 1 mole SO3 (g)
b. Seawater in midwinter at 2oC or Seawater in midsummer at 23oC
c. 1 mole of CF4 or 1 mole of CCl4
2.) Three possible complete statements are given. Tell what is wrong/incomplete with each one, and then
make the statement correct.
a. For a process to occur spontaneously, the entropy of the system must increase
b. For a process to occur spontaneously, the entropy of the surroundings must increase
c. For a process to occur spontaneously, both the entropy of the system and the entropy of the
surroundings must increase
3.) Without referring to your appendix – predict the SIGN (positive or negative) for S
a. 2K(s) + F2 (g) → 2KF(s)
b. CaCO3 (s) + 2HCl(aq) → CaCl2 (aq) + H2O(l) + CO2 (g)
4.) Potassium iodide is used as a dietary supplement to prevent the iodine deficiency disease, goiter, and is
prepared by the reaction of hydroiodic acid and potassium hydrogen carbonate. Water, carbon dioxide
and potassium iodide are the products of this reaction. In reacting 245 grams of hydroiodic acid with
116 grams of potassium hydrogen carbonate, how many grams of potassium iodide are produced?
Which reactant is in excess? How many grams of the excess reagent remain after the limiting reactant
has run out? If the reaction had 82.14% yield, how many grams of potassium iodide were actually
made?
5.) Given the following reactions, predict the products using your solubility rules, write ionic equations for
all and net-ionic if necessary. Name each reactant and product! Do not forget to show phases!!
a. _______Pb(NO3)4 (aq) + _______NaCl(aq) →
Names:
Ionic:
Net-ionic:
b. _______HgCrO4 (aq)
Names:
+ _______Li2SO4(aq) →
Ionic:
Net-ionic:
c. _______H2CO3 (aq)
Names:
+ _______Ba(ClO3)2 (aq) →
Ionic:
Net-ionic:
d. _______FeCl2 (aq)
Names:
+ _______LiNO3 (aq)
→
Ionic:
Net-ionic:
e. _______Na3PO4 (aq) + _______Cr(C2H3O2)3 (aq) →
Names:
Ionic:
Net-ionic: