Recrystallization Experiment P.5 by Jessica Dang

Flask

17hovp271 — 2013-11-15 02:12:19 UTC

Materials

17choateab232 — 2013-11-16 15:36:10 UTC

The materials are:

Controlled Varieables: NaCl. at 1.13 grams and 25 mL of water

Glass: Beaker, graduated cylinder, watch glass, and flask

Other: Hot plate, rubber tongs, and electronic balance

Trial #1

17choateab232 — 2013-11-16 15:47:52 UTC

PROCEDURE-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

17dangjv021 — 2013-11-17 01:30:49 UTC

17hovp271 — 2013-11-17 16:45:02 UTC

Flask with Salt

17hovp271 — 2013-11-17 16:52:31 UTC

17hovp271 — 2013-11-17 16:54:09 UTC

Flask with Water

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17hovp271 — 2013-11-17 16:58:05 UTC

Beaker with Salt on Hot Plate

17hovp271 — 2013-11-17 17:00:00 UTC

Water boils and starts to evaporates

17hovp271 — 2013-11-17 17:03:20 UTC

17hovp271 — 2013-11-17 17:05:05 UTC

17hovp271 — 2013-11-17 17:06:05 UTC

1.74 g of salt left

17hovp271 — 2013-11-17 17:08:30 UTC

FLOW CHART--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

17hovp271 — 2013-11-17 17:19:08 UTC

Step 1

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First you take your flask and measure

about 1-2g of salt

Step 2:

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Then you pour about 25ml of sink water

or fresh water into the flask filled with salt.

Step 3

17hovp271 — 2013-11-18 15:41:06 UTC

Next you transfer the flask with salt

and water into a beaker of any size.

(make sure all the salt gets transferred

into the beaker.

Step 4:

17hovp271 — 2013-11-18 15:42:14 UTC

After you have transferred the liquid from the flask to the beaker, you then place a watch glass on top of the beaker, and place the beaker onto the hot plate

Step 5;

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Once the beaker is on the hot plate, wait

for all of the water to evaporate leaving only

remains of salt left.

Step 6:

17hovp271 — 2013-11-18 15:47:14 UTC

When all the water evaporates and

only salt is left, remove the beaker

onto a cool surface and wait to cool.

Step 7:

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After the salt has cooled down, measure

the beaker with the salt in it and see

how much is left.

Step 8:

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After the experiment is complete, remember to calculate everything!

ANSWER QUESTION 2

17dangjv021 — 2013-11-18 21:28:25 UTC

2. If the percent error was positive, some of the logical solutions would be that maybe you didn't zero off the balance before you weighed the salt all the way, you might not have burned the water off all the way, or if you didn't use a watch glass and shared a hot plate the salt from one of the other beakers salt could have "jumped" into yours.

ANSWER QUESTION 3

17dangjv021 — 2013-11-18 21:30:45 UTC

The ESLR's that were address in this activity is responsible members of society because we all worked together as a group and we demonstrated a good work ethic. We are also critical thinkers because we put our knowledge together to find out how much salt went missing and how much we gained. We also make well-informed choices because we had to choose how much salt we should put in our beaker and to measure how many grams there were.

ANSWER QUESTION 4

17dangjv021 — 2013-11-18 21:32:55 UTC

3. Our percent error was negative and some of the logical reasons why would be that we didn't measure the salt correctly and there was less than we thought, if we weren't using the watch glass, which we were, some of our salt could have jumped into someone else's beaker, or maybe we didn't zero off the beaker right.

Purpose: You will learn to

17hovp271 — 2013-11-19 21:14:51 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