Nerdy Science Blog

Scientists had been conducting Avalanche experiments by burying pigs in snow at Austrian Alps. The purpose of the experiments was to find out the factors human are able to survive in an air pocket in snow without suffering permanent brain damage. Although anaesthesiologists said the pigs were sedated and anesthetized beforehand to minimize sufferings of the pigs, their experiments were protested by various animal rights groups. The growing media pressure forced scientists to stop the experiments.

(news [pic])

Back in secondary school, “acid rain” was one of my presentation topics. The fact that acid rain erode and ruined the statues and buildings amazed me. Why is it happening?

What is acid rain?

Distilled water which is neutral has pH 7. Anything that is less than pH 7 is considered as acidic. Normal rain which is unpolluted is slightly acidic, somewhere around pH 5.6. This is due to the reaction of carbon dioxide and water forming carbonic acid.

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Acid rain is the result of human activity. It is normally used to refer to the acidic deposition in rain, snow, dew, fog, or dry particles. There are different types of acidic precipitation that can be found in acid rain, which are:

1. Sulfurous acid [H₂O₂ (aq) + H₂SO₃ (aq) → H₂SO₄ (aq) + H₂O (l)]
2. Sulfuric acid [H₂SO₄]
3. Nitric acid [3NO₂ (g) + H₂O → 2HNO₃ (aq) + NO (g)]

Normal rainwater is however weakly acidic because rainwater contains dissolved CO₂ from the air.

What is rock?

Rock here is referred to marble and limestone, which are both consisted of calcium carbonate, CaCO3 (just like eggshell). They are commonly used in architecture, especially in constructing buildings, monuments and statues. However calcium carbonate is reactive to acid solutions. When acid rains have contact with the limestone or marble, they will erode.

For example, limestone building contacts with sulfuric acid rain.

CaCO₃ (n) [building] + H₂SO₄ (aq) [acid rain] → Ca²⁺ (aq) + SO₄^2- (aq) + H₂O + CO₂

Limestone or marble (calcium carbonate) buildings or monuments surface will be damaged and destroyed due to erosion.  Image (right) showed the corrosive effects of acid rain and wind that damage the carving of St. Peter (source).  The cleaning of limestone buildings cannot be done with acid-based cleaning chemicals.  Only neutral or mild alkaline-based cleaner can be used to clean the buildings or monuments.

Experiment

Simple experiment can be done to observe the effect of acid rain on limestone.  All you need are:

• 3 drinking glasses
• lemon juice
• vinegar
• water
• 3 chalks

Procedures:

1. Fill glass 1 with 1/2 glass of lemon juice, glass 2 with 1/2 glass of vinegar, and 1/2 glass of water in glass 3.
2. Then chuck one piece of chalk into each glasses (make sure part of the chalk is in the liquid).
3. Check the glasses few days later.

After couple of days, you will see that the chalks in the lemon and vinegar glasses are dissolved.  This is due to the calcium carbonate (chalk is consisted on calcium carbonate) reacts with the acids in lemon juice and vinegar.

Chinese Idiom.

There is a Chinese idiom “the drops of water penetrate the rock”.

Rock bastard, “Hey, what are you doing here?”

Water, “I want to pass through you.”

Rock bastard, “Haha, what makes you think you can pass through me?  You are just a tiny little rain drop.”

Water, “I will pass through you!  You just need to wait and see!”

After thousands of years, the water finally made a hole through the rock and passed through it.

The meaning of this idiom is to show that if you have power of perseverance, you can do anything.

England’s White Cliffs of Dover

England’s White Cliffs of Dover is composed of chalk (calcium carbonate) and the cliff face erodes at the rate of one centimetre per year.  If you lean against the cliffs, your body will be covered with white powder.

I just read this article by Anne Marie Helmenstine, Ph.D., from about.com chemistry. The tutorial is useful for many students.

1. Title page
2. Title
3. Introduction / Purpose
4. Materials
5. Methods
6. Data
7. Results
8. Discussion or Analysis
9. Conclusions
10. Figures & Graphs
11. References

When I was in my middle school year in Malaysia, science students are not required to include references list in their report. I think that is a bad thing to do in science education. When I went to college and university, I found that many Malaysian students tend to plagiarize other works.

(link [pic])

I am doing yeast (S. cerevisiae) transformation, one of the magic ingredients is salmon sperm DNA, which work as DNA carrier. We had good laugh over this name.

“Sperm? Haha! What is the sperm doing in the experiment?”

“Human one can arr? Ask him (our cute lab technician) to donate to you lah~!”

“Yewww~~~”

No doubt, my lab mates also get excited by the name of the ingredient.
Read more »

All you need are:

1. One Glass (big enough to put an egg in, not your shot glass for drinking)
2. One Raw Egg
3. Vinegar

What you need to do:

1. Put the egg in the glass and soak with vinegar. (Make sure it is fully covered by vinegar)
2. Leave them for few hours and you can observe the changing of the egg.
3. When the egg fizz, take it out and squeeze it softly, does it feel like rubber ball?
4. Leave the egg back to the vinegar for another week.
5. After one week, take the egg out and drop it on a bowl, and guess what happen? It bounces!

What are the uses of this simple experiment to do bouncy egg?

• If you are too poor to buy a rubber ball to play.
• You can compete with your friends and see whose eggs bounced higher. (Call the game “who-is-the-ballless-one”)
• You simply just scare your friends with these eggs.
• You can use these eggs during the protest, in stead of breaking all the eggs you throwing at their windows, try to reuse the eggs.

Why is it happening?

The process called ‘decalcification’ occured when the egg soaked in the vinegar. Vinegar (acetic acid) actually reacted with the calcium carbonate of the eggshell. When the egg soaked in the vinegar and began to fizz, it indicated the reaction was happening and vinegar dissolved the eggshell. The reaction is as following

2CH₃COOH (acetic acid a.k.a. vinegar) + CaCO₃ (calcium carbonate a.k.a. eggshell) → H₂O (water) + CO₂ (carbon dioxide, which was the fizz) + Ca(CH₃COO)₂ (Bouny eggshell)

Instead of using egg, you can also try to use bones to do this and give your dog a good bite. Maybe you can make bouncing bones and sell to your local toy stores.

Found this video at metacafe:

Make Amazing Bouncy Egg! – For more amazing video clips, click here(Picture)