7.2 Scientific interpretation - Group 1


    Fill in the table below (the 3rd column) and write up the scientific explanation of your partners'experiment. Your explanation must have been validated by your partners and your science teacher.

    Country Experiment Interpretation

    by Spain 1 group1

    The vinegar reacts with the shell of the egg. It is a chemical reaction, the calcium carbonate CaCO3 from the shell reacts with the vinegar CH3COOH (acetic acid) as it is a basic acid. So, carbon dioxyde CO2 and acetate calcium are produced accordind to this reaction:

    CaCO3 + 2CH3COOH -> Ca2+ + 2 CH3COO- + CO2, H2O

    The eggshell diassapears. The egg bounces, because the transparent shell that has the egg inside, does not break, and the egg takes more water than usual. It is the same action when you put water into a balloon.That´s why, the egg is stronger than usual.

    OK (I gave some details like the chemical reaction) . N.Hoang

    Spain 1

    (Pais Vasco)

    by French group 1

    When you cool down a bottle, the air in the bottle becomes colder. After that  when the bottle goes back at room temperature,the temperature inside the bottle increases. It results that, the pressure inside the bottle increases. Therefore the pressure forces due to the air inside push the coin upwards.


    OK (2nd revision). N.Hoang


    by Spain 2 group 1

    When they drop the baking soda into the glass with vinegar, the balloon swells.Maybe because a gas is produced in the chemical reaction.

    OK ... but .. which is the gas?

    ML Tibaldeschi

    Spain 2


    by Italian group 1

    Explanation: you heated the can on the burner and made the water 
    inside boil. As you did this, the water vapor from the boil forced air out of the can. 
    Once the can was filled with hot water vapor, it was cooled quickly  by turning it 
    upside down and submerging it in the cold water. The cooling process caused 
    the water vapor inside the can to condense. Which in turn created a partial 
    vacuum. The partial vacuum generated low pressure inside the can (lower than 
    the 10^5 Newton per square meter that surrounds us, i.e. the standard air pressure). Then the higher air pressure outside the can crushed it. The can was crushed / collapses when the air pressure outside became  greater  than the pressure inside. That pressure difference was greater than the can was able to withstand.