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

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

OBSERVATION THERE ARE TWO TYPES OF MIXTURE: Sometimes, when you mix two liquids like oil and water, one of these goes on top of the other staying on the surface. Sometimes, if you mix different liquids, they can become a new liquid all in one.

Questions Which liquid forms the lowest layer? Which liquid forms the highest layer? What happens if you mix the liquids together?

Hypothesis Our first hypothesis is that the position of a layer made of a certain liquid depends on the density of that liquid: liquids with a higher density will sink and liquids with a lower density will form a layer above the other. Our second hypothesis is that liquids with molecules similar to molecules of other liquids will mix forming a new and bigger layer formed of a new liquid.

PREDICTIONS We predict that the water, which is denser, will remain at the lowest layer, while the ethyl alcohol, that is less dense, will remain at the top. We also predict that water and oil will not mix.

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. 7

DO TEST 2: In test 2 we used: water, extra virgin olive oil and peanut oil First we put all of those liquids in a glass. Then we mixed them with a little spoon. We took pictures before and after mixing.

DO TEST 3: In test 3 we used: dish soap, olive oil and water. First we put all of those liquids in a glass. Then we mixed them with a little spoon. We took pictures before and after mixing.

TEST 1: REACTION AFTER MIXING Test 1: you can see that at the bottom there is ethyl alcohol mixed with water, at the top there is olive oil that created bubbles.

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.

TEST 3: REACTION AFTER MIXING Test 3: you can see that, mixing all up, at the bottom there is the dish soap, at the center there is the olive oil, partially mixed with both liquid and forming foam.

ANALYSE DATA: before mixing LOWEST LAYER MIDDLE LAYER HIGHEST LAYER EXPERIMENT 1 water olive oil ethyl alcohol EXPERIMENT 2 peanut oil EXPERIMENT 3 dish soap .

ANALYSE DATA: after mixing LOWEST LAYER MIDDLE LAYER HIGHEST LAYER EXPERIMENT 1 mix of water and ethyl alcohol oil (small bubbles) EXPERIMENT 2 water “sort of” mix of peanut oil and olive oil EXPERIMENT 3 mix of soap and water oil partially mixed with soap and water (foam) .

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.