orgnic questions

Question 1

The uncertainty in each of the temperature readings from the thermometer in this
experiment was ±0.25 °C. This gave an overall uncertainty in the temperature
rise of ±0.5 °C.
Calculate the percentage uncertainty for the use of the thermometer in this
experiment.

Answer 1

(100 x 0.5 / 38 =) 1.3 or 1.32 o

Question 2

The student said correctly that using a thermometer with an overall uncertainty for
the rise in temperature of ±0.5 °C was adequate for this experiment.
Explain why this thermometer was adequate for this experiment.

Answer 2

Idea that heat loss is more significant issue OR
Idea that temperature change/rise is (significantly / much)
bigger than uncertainty

Question 3

Explain why 1,1,1-trifluoroethane does not lead to the depletion of the ozone in
the upper atmosphere.

Answer 3

Does not contain Cl or does not release Cl (atoms/radicals)
or no C-Cl bonds
or C-F bond(s) strong / does not break / no F (atom/radicals)
released

Question 4

Anti-bumping granules are placed in the flask when refluxing.
Suggest why these granules prevent bumping.

Answer 4

form small(er) bubbles or prevent large bubbles