This experiment is for advanced students.

Ever use soap? Sodium hydroxide (NaOH) is the main component in lye soap. NaOH is mixed with some type of fat (vegetable, pig, cow, etc). Scent can be added for the ‘pretty’ factor and pumice or sand can be added for the manly “You’re coming off my hands and I’ll take no guff” factor. Lots of people still make their own soap and they enjoy doing it.

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One of the coolest uses for sodium hydroxide is in tissue digestion. By “tissue” we mean meat, bone, sinew…..meaning bodies! People who pick up dead animal (road kills) for the county dump their catch in barrels containing sodium hydroxide. The NaOH eats everything up and then the “sludge” is dumped in the landfill. They used NaOH to make them decompose. So this stuff is nasty and should never be touched with your bare hands!!

Materials:

• Erlenmeyer flask
• Alcohol burner
• Lighter
• Heating rod
• Sodium carbonate (Na₂CO₃) (MSDS)
• Calcium hydroxide (Ca(OH)₂) (MSDS)
• Measuring spoon
• Water
• Tripod stand
• Wire screen
• Chemistry stand
• Test tube holder
• Test tube rack
• Test tube
• Filter paper
• Funnel
• Stock bottle for NaOH storage (MSDS)

Don’t inhale any fumes from reactions or powder welling out of chemical containers, especially calcium hydroxide dust. We want to test our product to see if it is NaOH. It should turn red litmus blue.

We will perform a bunch of operations in this lab.

1. Heating our calcium hydroxide / sodium carbonate mixture to create calcium carbonate and sodium hydroxide.
2. Filter out the calcium carbonate to collect the sodium hydroxide.
3. Test our sodium hydroxide product for the properties of NaOH.

C3000: Experiments

Download Student Worksheet & Exercises

Here’s what’s going on in this experiment:

Ca (OH)₂ + Na₂CO₃ –> 2NaOH + CaCO₃

Calcium hydroxide and sodium carbonate are combined in water and heated to produce sodium hydroxide and calcium carbonate

This is a double replacement reaction because the calcium ion and the sodium ion have swapped places

Cleanup: We are going to clean everything thoroughly after we finish the lab. After cleaning with soap and water, rinse thoroughly. Chemists use the rule of “three” in cleaning glassware and tools. After washing, chemists rinse out all visible soap and then rinse three times more.

Storage: Place cleaned tools and glassware in their respective storage places.

Disposal: Liquids must be neutralized with vinegar, if a base, or baking soda, if an acid, before washing them down the drain. Before actually washing them down the drain check again with litmus paper to ensure that they have been neutralized. Solids are thrown in the trash.

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