Question

what experimental error usually occur in the reaction of hydrogen peroxide and bleach experiment? how this error affect the volume of oxygen collected?

Answer 1

The reaction between hydrogen peroxide and bleach is

2 NaClO + H2O2 -------------> NaCl + H2O + O2

Oxygen can be collected over water in a inverted tube closed on one side (or inverted measuring cylinder).

(a) In the lab, during the experiment, we usually do not adjust the level of water inside the measuring cylinder to the level of water outside the measuring cylinder.

Due to this, the pressure of oxygen and its volume is incorrectly measured.

(b) Volume of oxygen collected is too high which means that the pressure outside the measuring cylinder is too low.
This happens when the level of water in the measuring cylinder is lower than the level of water outside the measuring cylinder.