Photo Session

ATTENTION to Maths & Science Club's Board of Directors!!!

There will be a photo session on the 15th of April(Wednesday) at 11.05 am.

Coca - Mentos Experiment (7th April 2009)

We had loads of fun getting together, conducting fun and easy experiments and at the same time learning some interesting scientific facts!!

This is a brief scientific report on the experiment:

Aim

To investigate the reaction between Diet Coke and Mentos candies

Hypothesis

The reaction between the Diet Coke and the Mentos candies results in an eruption.

Materials

A handful of Mentos and two liter of Diet Coke

Procedure

8 Mentos candies were dropped into a bottle of Diet Coke.

Observation

An eruption occured.

Inference/Explanation

This reaction was thought to occur because of rapidly expanding carbon dioxide bubbles inside once the Mentos were introduced to the carbonation.

Caffeine, potassium benzoate, aspartame and carbon dioxide gas contained in the Diet Coke and the gelatin and gum Arabic ingredients of te Mentos all contributed to the geyser effect.

When Mentos candies were dropped into the Diet Coke, the gelatin and gum Arabic of the candy dissolved and broke the surface tension. This disturbed the water mesh, so that less work were needed to expand and form new bubbles. Each mentos candy has thousands of tiny pores all over its surface. These tiny pores function as nucleation sites, perfect places for carbon dixide bubbles to form. As soon as the Mentos entered the coke, bubbles were formed all over their surface. They quickly sinked to the bottom, causing carbon dioxide to be released by the carbonated liquid with which they came into contact along the way. The sudden increase in pressure pushed all of the liquid up and out of the bottle.

Discussion

1) Why do we use Diet Coke instead of the regular Coke?

The reason that people use diet coke is because they do not contain sugar like regular coke. Non-diet coke contains a large percentage of sugar molecules, which help hold onto the carbon dioxide a lot better, thus preventing nucleation from occuring as quickly, resulting in a weaker reaction.

The absence of sugar in the diet coke residue after the geyser effect caused the resulting mess to be non-sticky and this makes clenup much easier.

Conclusion

The reaction between the Diet Coke and the Mentos candies results in an eruption. Therefore, the hypothesis is accepted.