In the Classroom

 

Science Discipline(s)

Chemistry

Topics

  • States of matter
  • Carbonation
  • Surface area
  • Chemical reaction

Activity Title

Diet Coke and Mentos

Materials

  • Piece of paper*
  • Playing card*
  • Googles
  • 2-Liter bottle of diet coke
  • A pack of Mentos

You can also use a commercial Mentos Launcher tube for the starred (*) items.

Procedure

Might want to run practice experiment before performing in front of students. Also highly advised to perform outside because soda will splash everywhere.

  1. Open the two liter bottle of diet coke
  2. Roll the piece of paper so that Mentos can fit in that roll.
  3. Hold tube of paper and put the playing card at the bottom of the tub.
  4. Load 4-6 Mentos in the tube with the playing card holding them so they don’t fall out.
  5. Carefully hold the tube of Mentos and card over the bottle, lining up the tube and mouth of the bottle
  6. Pull the card out from the tube letting the Mentos drop in the two-liter bottle
  7. Move out the way

 

Questions

  1. What experimental variables do you believe impact how high of a fountain you get in this experiment? How would you test whether these variables affect the height of the fountain?
  2. What is happening when you place Mentos in diet coke?
  3. Is this a physical or chemical reaction?
  4. Will the number of Mentos dropped in the diet coke affect the height of the coke being splashed up?
  5. How come regular soda doesn’t work as well as diet?

 

Explanation

A carbonated beverage is packed full of dissolved carbon dioxide gas, which interacts with water molecules. The gas is kept in solution by the bottle’s pressurized condition. When you pour soda in a glass, some CO2 gas escapes and forms foam, but most stays inside the liquid because of surface tension. A single piece of Mentos candy may look smooth, but actually it has many tiny bumps coating the whole surface. This rough surface allows the carbon dioxide gas and water to break very easy which causes the eruption. A key factor in this experiment is the speed at which the Mentos fall through the soda.

Next Generation Science Standards

  • PK – grade 3 students : K-LS1-1; 1-LS1-1; 1-LS1-2; RI.1.1; RI.1.2;RI.1.10; W.1.7; 2-PS1-1; 2-PS1-2; 2-PS1-3; 2-PS1-4; RI.2.1; RI.2.3; RI2.8; RI.2.7; MP.2; MP.10
  • Grade 4 – 6 students: 4-PS3-4; 4-PS3-3; 4-PS3-3; W.4.7; 5-PS1-1; 5-PS1-2; 5-PS1-3; 5-PS1-4; W.5.7; W.5.8; MP.5; MP.2
  • Middle school students: RST.6-8.3; 6.RP.1; MS-PS1-1; MS-PS1-2; MS-PS1-3; MP-PS1-4; MP-PS1-5; MP-PS1-6; RST.6-8.3; RST.6-8.7