Question

1. A student was given a sample of an anhydrous salt to anazlyze, using the procedure described in this experiment. The student weighed the sample but decided to do the experiment the following day. The weighed sample was left unconvered on the bench overight.

a) What error(s) might result if the student used this salt sample in a determination the following day? Briefly explain.

b) Would the student avoid any error(s) desribed in (a) by reweighing the salt sample on the following day, before doing the experiment?

c) Briefly explain what effect the use of a glass beaker in place of the pressed polystyrene cup would have on the expected H(Hydration).

2. A student doing this experiment decided to check the accuracy of the calibration of the the thermometer. When placed in a beaker of boiling water, the thermometer indicated 103.5 °C. Would using this thermometer in this experiment cause any erros in the calculated H(dissolution)? Briefly explain.

3. There is a large difference between H (dissolution) of an anhydrous salt dissolved in water and H(dissolution) of the hydrated form of the same salt dissolved in water. How do the enthalpy of dissolution, the crystal lattice energy, and the solvation energy of the two salts relate to these experimental observations?

Answer 1