Make your own Mummy!Ever wonder why you get thirsty when you eat salty foods? That's because salt is a desiccant desiccant /des·ic·cant/ (des´i-kant) 1. promoting dryness. 2. an agent that promotes dryness. des·ic·cant n. --it helps remove water from things, including human bodies. Experiment with different salt compounds and discover which makes the best mummified mum·mi·fy v. mum·mi·fied, mum·mi·fy·ing, mum·mi·fies v.tr. 1. To make into a mummy by embalming and drying. 2. To cause to shrivel and dry up. v.intr. apple! You NEED Fresh apple * knife * 250 ml (1 cup) table salt * 250 ml Epsom salts Epsom salts, common name for magnesium sulfate heptahydrate, MgSO4·7H2O, a water-soluble bitter-tasting compound that occurs as white or colorless needle-shaped crystals. * 250 ml baking soda baking soda: see sodium bicarbonate. * 4 12-oz plastic cups * marker * masking tape * food scale * data table (from Teacher's Edition, p. TE5) * shelf shaded from sunlight To Do: 1. Put a piece of tape on each cup and label the cups as follows: Control, Baking Soda, Epsom Salt, and Table Salt. 2. Slice the apple into quarters so you have four slices similar in size. Place one slice in front of each cup. 3. Weigh the apple slice in front of the Control cup, and record its weight on the data table. Drop the apple inside its cup. 4. Repeat Step 3 with the three other apple slices. Then pour baking soda, Epsom salt, and table salt in their respective cups. Make sure each apple slice is covered completely. 5. Set the cups on a shady shelf, away from direct sunlight. Let them sit for seven days. 6. After a week, take out each apple slice and brush off as much salt as possible. (Do not rinse the apple because that will rehydrate re·hy·drate v. 1. To cause rehydration of something. 2. To replenish the body fluids of an individual. it.) Weigh each slice, and record the new weight in your data table. Then, calculate the amount of moisture lost by subtracting each slice's final weight from the initial weight. CONCLUSIONS Which compound works best at "mummifying" an apple? Where did the moisture in the slices go? DON'T STOP NOW! Embalmers used a mixture of salts to dry out Egyptian mummies. Try different combinations and proportions of baking soda, Epsom salt, and table salt to "mummify mum·mi·fy v. mum·mi·fied, mum·mi·fy·ing, mum·mi·fies v.tr. 1. To make into a mummy by embalming and drying. 2. To cause to shrivel and dry up. v.intr. " apple slices. Which combination works best? |
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