Fun Facts In Chemical Engineering

Concept through fun facts

We all are surrounded by chemicals in our life. We handle a lot of chemicals nearly everyday, unknowingly. A variety of chemical processes are going on around us, and we perform some of them ourselves, and we don't even realize! This section explains the different subject-wise concepts in a much friendly way than how it is taught in your colleges! So just click the subject which you want to read about, from the above list, and enjoy your learning!

Fluid Mechanics

Lakes freeze from top to bottom:

As the surface water of the lake cools and reaches 4⁰C, its density increases.
This colder, denser water sinks, displacing the warmer, less dense water at the bottom, which then rises to the surface to be cooled.
This continues until the entire body of water is near 4⁰C.
Water reaches its maximum density at 4⁰C, hence it settles down.
Cooling from 4⁰C to 0⁰C is called the anomalous expansion phase, in which the density decreases.
Water molecules begin to form an open lattice-like structure in preparation for freezing, which takes up more space and makes the liquid dense.

A needle floats on water:

A needle floats on water because of its surface tension.
When the needle is placed gently on the water's surface, the cohesive forces between water molecules create a flexible, stretched membrane (aka skin formation) that supports the needle's weight.
The upward forces of this stretched surface, due to surface tension, balance the downward force of gravity acting on the needle.
Other fun facts based on the same phenomenon are - leaves floating on water, mosquitoes lay eggs on water surface, adding sulfur powder to urine sample to check for the presence of bile - if it floats, no bile present but if it floats, then bile is present, which means it could be jaundice.

Astronauts can drink water on the moon:

The most common way astronauts drink water, both on the Moon and in orbit, is by using sealed collapsible pouches and straws equipped with one-way valves.
The water is contained in a pouch, which is a closed system.
The astronaut uses a special straw to suck the water out of the pouch. This suction is necessary because there's no strong gravitational pull to make the liquid flow downward or towards the opening of a container.
The sucking of water from a straw is based on the phenomenon of capillary action.

Application of Bernoulli's theorem

What does Bernoulli's theorem tell us?
Bernoulli's theorem tells us a simple thing about fluids - as fluid velocity increases, the pressure / potential energy decreases.
This section comes under fluid mechanics, but since there are many applications, it is been shown separately.
Here you'll find many interesting fun facts which will help you understand what is Bernoulli's theorem, in simple ways.

Inward movement of a curtain in a bathroom while the shower is open at full speed
- Have you ever observed that while having a bath with a shower, the curtain besides it moves inward as the water flows.
- This curtain moves because of the speed of the water from the shower.
- But wait, shouldn't this force push the curtain instead of pulling?
- Here's the twist - since the fluid (water from the shower) velocity is high, it decreases the pressure.
- Since the pressure is decreased, the curtain is pulled inside instead of getting pushed outward.
- This is also known as "Shower Curtain Effect" and this is an application of Bernoulli's principle.
You are told to stand behind the yellow line on a platform when a fast train is going to pass by
- Have you ever stood on a platform, irritated by a repeated announcement which says, "passengers are advised to stand behind the yellow line, as a superfast train is going to pass from platform number x".
- Do you know why they say so? Well, this is not a random instruction, this has a valid reason.
- When the superfast train passes in front of you, the speed of the train is too fast, nearly 100 km/hr.
- So, when the train passes, the air also flows with it in the same speed and the same direction.
- Since the air is also at such a high speed, if you are standing there, the air will pull you in, instead of pushing you back.
- You may have felt an inward pulling force when the train passes.
- This is not rocket science - this is Bernoulli's principle!
- The fluid (air) speed is around 100 km/hr, and this decreases the pressure in that area of the platform.
- Now, since the pressure is decreased, you feel it difficult to stand there, and you are pulled inside the air flow. This can cause an accident.
- So, as a chemical engineer, will you now take this precaution?

Chemistry and chemical technology

Onions bring tears to your eyes:

When an onion is sliced, it releases sulfenic acid which becomes a sulfur containing gas that eventually reaches your eye.
Your eyes produce tears to remove the irritant.

Flame of a gas stove looks blue in color:

The flame of a gas appears blue because complete combustion produces enough energy to excite and ionize the gas molecules in the flame.

When we burn wood, the fire looks orange in color:

When we burn wood, the fire appears orange in colour.
This is due to the presence of sodium. When sodium burns, it burns with an orange flame.

Mayonnaise inside the burger melts down after some time:

Hot patty transfers heat to the cold mayonnaise.
Temperature of the mayonnaise rises.
Viscosity decreases significantly.
Once viscosity decreases sufficiently, gravity can cause the sauce to migrate downward.
This is why warmed mayonnaise often accumulates near the bottom edge of the burger.
The emulsion becomes less stable and more fluid.
Pressure from the burger, gravity, and shear forces drive flow.
The mayonnaise spreads, seeps into the bun, and may partially separate.
So the "melting" of mayonnaise is primarily a thermally induced reduction in viscosity and emulsion stability, followed by fluid flow driven by pressure gradients, shear forces, capillary effects, and gravity.