Recrystallization Experiment by Marcel Cung [Student FVHS]

Group 1, Period 5

17cungm290 — 2013-11-19 16:25:04 UTC

Marcel Cung
Ellie Levitz
Brandon Wong

Procedure

17cungm290 — 2013-11-19 16:27:13 UTC

In our group, we decided to go with 2 grams of salt because it was a nice, even number, and we put that into the flask. After that, we measured, with the electronic balance, how much the beaker weighed, and then added 25 mL of water into the flask. We spun the flask with the water inside to make it dissolve quicker, and once it was completely dissolved and difficult to see, we put that into the beaker. After that, we put the beaker on top of the heating plate, with a watch glass on top of the beaker, so that salt would not be popping out as we boiled the water.

Pre Lab Discussion

17levitzes201 — 2013-11-19 21:22:38 UTC

Recrystallization is one way of isolating an ionic compound from a solution. If several ionic compounds are present in an aqueous solution, then a precipitation reaction may be performed to remove the unwanted ions. In this experiment, a known amount of NaCl will be dissolved in some water, and then recrystallized by boiling off the water.

Purpose: You will learn too

17levitzes201 — 2013-11-19 21:25:03 UTC

To perform and master a recrystallization of an ionic compound

To write a procedure for a simple experiment

To calculate for percent error in an experiment

To understand how results affect percent error

To identify sources of error in experiments

Materials Used

17levitzes201 — 2013-11-19 21:29:45 UTC

17wongbt287 — 2013-11-20 00:52:17 UTC

Beaker

17levitzes201 — 2013-11-20 01:51:03 UTC

Watchglass

17levitzes201 — 2013-11-20 01:52:20 UTC

Graduated Cylinder

17levitzes201 — 2013-11-20 01:54:10 UTC

Tongs

17levitzes201 — 2013-11-20 01:54:49 UTC

Flask

17levitzes201 — 2013-11-20 01:56:02 UTC

Electric balance

17levitzes201 — 2013-11-20 02:06:23 UTC

Heating plate

17levitzes201 — 2013-11-20 02:07:44 UTC

Salt (NaCl)

17levitzes201 — 2013-11-20 02:09:36 UTC

Trial #1

17levitzes201 — 2013-11-20 02:23:09 UTC

Question #2

17levitzes201 — 2013-11-20 02:29:48 UTC

In Trial #1 our percent error was 2%. Our predictions have come to conclude that after the recrystallization, there was some salt on the watch glass due to the water boiling and popping. If we were to do a Trial #2, we would have weighed the watch glass before starting the recrystallization.

Question #3

17levitzes201 — 2013-11-20 02:49:02 UTC

If one of our trials was a negative, it would mean that we ended up having more then we wanted. Reasons of why this could've happened is if someone had their experiment boiling near ours. Another assumption could be that the beaker and/or flask we were using had little remaining salt inside of them. One last thought could be that the 25 mL of water we used may have contained salt inside of it already.

Trial #2

17wongbt287 — 2013-11-20 02:56:30 UTC

Question #4

17wongbt287 — 2013-11-20 03:23:37 UTC

The ESLR that was used during our experiment was " Work well With Others " This ESLR was used during the experiment because when my group members and I had some disagreements we resolved it quickly. Another ESLR that was used during our experiment was " Will Apply Knowledge to solve problems " This ESLR was used during the experiment when we forgot the percent-error equation, Marcel thought back and remembered.

Trial #2

17cungm290 — 2013-11-20 03:37:40 UTC

Question #1

17cungm290 — 2013-11-20 03:42:05 UTC

Trial #1

17cungm290 — 2013-11-20 03:42:14 UTC

Flow Chart

17levitzes201 — 2013-11-20 03:55:25 UTC