Extraction of Salt from a Mixture

Extraction of Salt from a Mixture

Procedure:

        In order to calculate the percentage of salt in an unknown mixture of salt and sand, we must extract the sand from the salt. To accomplish this, we must first measure about two grams of the mixture which we will extract the sand from. In order to separate the two substances, we must add water to the mixture; this will cause the salt to dissolve in the water, which will be filtered, leaving the sand. Will emptying the mixture into the filter we must be careful and make sure all the grains of sand are emptied into the filter for this will affect our results. Once separated, the sand will be wet which will make the sand seem heavier thus affecting our results. To avoid this we must dry the sand. After drying, both the filter and the container the sand is to be weighed in must be weighed for this too will affect our results. We then measure it with the sand and subtract in order to receive the mass of the sand. With this information we can calculate the % of sand and the % of salt in the mixture by dividing the mass of the sand/salt by the mass of the mixture and multiply that by 100.

Pre-lab Questions:

1. If, for each trial, a different amount of initial mixture was used the results may be slightly effected, but it shouldn’t be a large difference considering the percentage of salt should be the same throughout the mixture no matter how much you take out in the beginning.
2. Whether you base the percentage of salt on the mass of the sand or the mass of the salt may slightly effect the result, but it shouldn’t be a great difference unless an error was made along the way since you should not have lost nor gained any salt or sand during the procedure if done correctly.
3. Again, whether you base the percentage of salt on the mass of the sand or the mass of the salt may slightly effect the result, but it shouldn’t be a great difference unless an error was made along the way since you should not have lost nor gained any salt or sand during the procedure if done correctly.
4. If the percent of salt obtained is greater than the actual value then you either measured the amount of sand incorrectly or you did not get all of the sand into the filter. If the percent of salt is less than the actual value then you either measured the amount of sand incorrectly or you forgot to weigh the container or the filter the sand was in, increasing the mass of the sand and decreasing the mass of the salt.

Results:

AVE: 21.125% Salt- The average of the percentages of salt is used to calculate the precision of our answers in this experiment since we can’t calculate the accuracy of our answers.

DEV 1: 1.875%[pic 1]

DEV 2: 1.875%          The deviation from the average also aids in calculating precision.