Question

Prelaboratory Questions: Name: Section: 23170 1. What potential source of laboratory accident is present in this experiment? Explain the procedure you will follow to minimize this hazard. What two precautions will you follow to prevent injury to yourself, and what will you do to avoid injuring another in the event the accident does occur? 2. Another thermal decomposition that produces oxygen begins with silver oxide: 2Ag2Os)-4Ags) + O2) In a hypothetical experiment, a student collected the following data: Mass of crucible: 30.296g Mass of crucible + Agzo: 38.623g Mass of crucible + Contents after decomposition: 38.0619 Calculate the following: a. The starting mass of Ag2O: b. The mass of oxygen released c. Experimental percentage of oxygen in Ag2O from the data: d. Theoretical percentage of oxygen in Ag20 from the formula: e. Percent error:

Answer 1

1. I don't know exactly which is the experiment you'll be performing, but the main hazard seems to be the heating for the thermal decomposition and the handling of hot lab material. Precautions: handle the crucible with correct thongs.

2. a. The starting mass of Ag₂O is the difference between crucible + Ag₂O and the crucible alone: 38.623 g - 30.296 g = 8.327 g.

b. The mass of oxygen released comes from the difference between the crucible + Ag₂O and the crucible after the decomposition: 38.623 g - 38.061 g = 0.562 g.

c. The experimental percentage of oxygen is:

0.5629 -6.749 100 8.3279

d. The theoretical percentage is:

169 100.215.79 = 7.416

e. The percent error is then

100. 6.749-7.416 7.4169 = 8.999

Almost 9%.