ISTITUTO COMPRENSIVO TRENTO 5 Scuola secondaria di primo grado “G. Bresadola”

1. ISTITUTO COMPRENSIVO TRENTO 5 Scuola secondaria di primo grado “G. Bresadola” OPEN DAY SCIENZE quinta edizione a. s. 2018/2019 30 novembre 2018

2. Bottle of layers ELENA TAZZARI, GIULIA BAILONI LARAIB ASIF, ELISA VAEL Classe 1A

3. OBSERVATION THERE ARE TWO TYPES OF MIXTURE: Sometimes, whenyou mix twoliquids like oil and water, one of thesegoes on top of the otherstaying on the surface. Sometimes, ifyou mix differentliquids, they can become a new liquidall in one.

4. Questions • Whichliquidforms the lowestlayer? • Whichliquidforms the highestlayer? • Whathappensifyou mix the liquidstogether?

5. Hypothesis • Our first hypothesisisthat the position of a layer made of a certainliquiddepends on the density of thatliquid: liquids with a higherdensitywillsink and liquids with a lowerdensitywillform a layerabove the other. • Our second hypothesisisthatliquids with moleculessimilar to molecules of otherliquidswill mix forming a new and biggerlayerformed of a new liquid.

6. PREDICTIONS • Wepredictthat the water, whichisdenser, willremainat the lowestlayer, while the ethylalcohol, thatisless dense, willremainat the top. • Wealsopredictthat water and oilwillnot mix.

7. DO TEST 1: In test 1 we used: water, olive oil and ethyl alcohol • First we put all of those liquids in a glass • Then we mixed them with a little spoon. • We took pictures of the result before and after mixing.

8. DO TEST 2: In test 2 weused: water, extra virgin olive oil and peanutoil • First we put all of thoseliquids in a glass. • Thenwe mixed them with a littlespoon. • Wetook pictures before and after mixing.

9. DO TEST 3: In test 3 weused: dish soap, olive oil and water. • First we put all of thoseliquids in a glass. • Thenwe mixed them with a littlespoon. • Wetook pictures before and after mixing.

10. TEST 1: REACTION AFTER MIXING • Test 1: you can seethatat the bottom thereisethylalcohol mixed with water, at the top thereis olive oilthatcreatedbubbles.

11. TEST 2: REACTION AFTER MIXING • Test 2:you can see that the water remains at the bottom and peanut oil is partially mixing with olive oil.

12. TEST 3: REACTION AFTER MIXING • Test 3: you can seethat, mixing all up, at the bottom thereis the dish soap, at the center thereis the olive oil, partially mixed with bothliquid and formingfoam.

13. ANALYSE DATA: before mixing .

14. ANALYSE DATA: after mixing .

15. CONCLUSIONS Our predictions were partially correct. • The water is always at the lowest layer except for the third experiment. In this case the densest liquid is the dish soap. • The water never mixes with oil except when the soap breaks oil’s molecules so that it partially mixes into water.