A Glass Bulb with a Volume of 250 $\rarr$ KCl + O₂
After the Apparatus Cools Back to Room

Multiple Choice

A glass bulb with a volume of 250.0 mL contains a small amount of solid potassium chlorate. It is connected to a mercury manometer. Upon heating the bulb, the following (unbalanced) reaction occurs:
KClO₃ $\rarr$ KCl + O₂
After the apparatus cools back to room temperature, 23°C, the difference in the mercury levels in the manometer is now 14.2 cm. Which of the following statements are true?
1) The mercury on the side of the tube connected to the manometer is higher than before.
2) About 1.9 x 10^-3 moles KClO₃ decomposed.
3) About 0.16 g KClO₃ decomposed.
4) The mercury on the side of the tube connected to the manometer is lower than before.
5) About 1.3 x 10^-3 moles O₂ were evolved.

A) 1, 2 and 5 only
B) 5 only
C) 2 and 4 only
D) 3 and 4 only
E) 4 and 5 only