Today we are going to investigate a product called Salt Sense® versus regular table salt.
(Public domain photograph of salt and pepper by Jon Sullivan)
According to the label of the product, Salt Sense® contains real salt, but there is “33% less sodium per teaspoon.” How is this possible?
Prior to starting, answer the following questions:
What do you know about salt and its structure? How might the company achieve its claim of 33% less sodium per teaspoon? Is there 33% less chloride as well?
- Iodized Table Salt
- Iodized Salt Sense
- Microscope or hand lens
- Petri dishes
- Measuring beakers or graduated cylinders
- Kitchen scale that can weigh grams
- Laboratory notebook or paper
- Pen for recording results
1. Place a small sample of table salt in one petri dish and a sample of Salt Sense® in a second petri dish. Look at the samples under the microscope.
Draw what you see for each sample. How might the differences you observe change the amount of sodium per teaspoon?
2. Calculate the density of each substance.
Density = mass/volume
Tare a measuring beaker on the scale (ask the instructor if you don’t know what “tare” means.)
Pour 20 ml of table salt in the beaker. Weigh the table salt in grams and record the weight.
Now tare the second beaker. Add 20 ml of Salt Sense® to the beaker and weigh it. Record the weight in grams.
Calculate the density of each sample. Which sample is less dense? How much less dense is it?
How might you make your results more accurate?
Manufacturer Diamond Crystal’s explanation of Salt Sense®
Check out this video about the history and chemistry of sodium chloride.
Credit: NBC Learn and the National Science Foundation (NSF)
Grow your own salt crystals at About.com
Using salt to melt ice at NBC Learn