- Some chemical compounds will dissolve in water, and some will not. Sometimes, two compounds that dissolve in water will react to form a new compound that is insoluble (does not dissolve). This new compound comes out of solution and is referred to as a precipitate.
- In this lab, you will react epsom salt with ammonia. These are both compounds that dissolve in water. Household ammonia contains ammonium hydroxide, and the chemical name for epsom salt is magnesium sulfate. Mixing ammonia and epsom salt causes a reaction which produces magnesium hydroxide as one of the products. Magnesium hydroxide is a white substance that does not dissolve well in water. After standing awhile, the white precipitate will settle to the bottom of the jar.
MATERIALS NEEDED:
1 teaspoon epsom salt
2 teaspoons household ammonia
Water
Measuring spoons
Spoon to stir
Small baby food jarPROCEDURE:
Fill the jar one-half full with water.
Add 1 teaspoon of epsom salt to the water and stir to dissolve.
Pour 2 teaspoons of ammonia into the jar. DO NOT STIR.Allow the solution to stand for 5 minutes. Observe the formation of the magnesium hydroxide precipitate as the ammonia mixes with the epsom salt solution. As it sits, the precipitate will settle to the bottom of the jar.
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- In this lab, you will react epsom salt with ammonia. These are both compounds that dissolve in water. Household ammonia contains ammonium hydroxide, and the chemical name for epsom salt is magnesium sulfate. Mixing ammonia and epsom salt causes a reaction which produces magnesium hydroxide as one of the products. Magnesium hydroxide is a white substance that does not dissolve well in water. After standing awhile, the white precipitate will settle to the bottom of the jar.
REACTING TWO COMPOUNDS
TO FORM A PRECIPITATE #2
INTRODUCTION: