AP Chem Unit 1 MC Quiz

5 H₂O₂(aq) + 2MnO₄^-(aq) + 6H⁺(aq) --> 2 Mn²⁺(aq) + 8 H₂O(l) + 5 O₂(g)

In a titration experiment, H₂O₂(aq) reacts with aqueous MnO₄^-(aq) as represented by the equation above. The dark purple KMnO4 is added from a buret to a colorless, acidified solution of H₂O₂(aq) in an Erlenmeyer flask. (Note: At the end point of the titration, the solution is a pale pink color.)

At a certain time during the titration, the rate of appearance of O₂(g) was 1.0 x 10^-3 mol/(L•s). What was the rate of disappearance of MnO₄^- at the same time.

• 6.0 x 10^-3 mol/(L•s)

• 4.0 x 10^-3 mol/(L•s)

• 6.0 x 10^-4 mol/(L•s)

• 4.0 x 10^-4 mol/(L•s)

CH3OH(g) --> CO(g) + 2H2(g) DH =+91 kJ/molrxn
The reaction represented above goes essentially to completion. The reaction takes place in a rigid, insulated vessel that is initially at 600 K.

  A sample of CH3OH(g) is placed in the previously evacuated vessel with a pressure of P1 at 600K. What is the final pressure in the vessel after the reaction is complete and the contents of the vessel are returned to 600 K?

• P1/9

• P1/3

• P1

• 3P1