CHE 11, Fall 1998
Quiz 4
October 9, 1998

Show your work for full credit. Give your answers with the correct number of significant figures.

Useful information:

1. Rust stains can be removed by washing a surface with a dilute solution of oxalic acid (H₂C₂O₄), according to the reaction shown below.

Fe₂O_{3 (s)} + 6 H₂C₂O_{4 (aq)} 2 Fe(C₂O₄)₃^3- _(aq) + 3 H₂O _(l) + 6 H⁺ _(aq)

(a) Is this an oxidation-reduction reaction? If so, what is being oxidized and what is being reduced? If not, why not? (2 points)

(b) What mass of rust can be removed by reaction of 1.0 L of 0.14 M solution of oxalic acid? (2 pts)

2. Predict the products for the following reaction, indicating which (if any) will be solids. (2 pts)

H₂SO_{4 (aq)} + Al(OH)_{3 (s)}

3. Consider the two containers of argon gas which are shown below. These containers are at constant temperature and contain the same number of gas particles. Which of the following statements about these gas samples is false? (2 pts)

(a) The average speed of Ar in both containers is the same.
(b) The kinetic energy Ar in both containers is the same.
(c) The force with which the Ar atoms collide with their container is the same in both containers.
(d) The frequency with which the Ar atoms collide with the walls of their container is the same in both containers.

4. Ethene is converted to ethane by the reaction shown. If 1250. L of ethene (C₂H₄) is reacted with 975 L of hydrogen (H₂) at 25.0 atm and 300 ^oC, what is the theoretical yield (in grams) of ethane (C₂H₆)?

C₂H_{4 (g)} + H_{2 (g)} C₂H_{6 (g)}