Most of us have likely spent the better part of the past year stuck at home because of the pandemic.
And it’s safe to say that the effort of doing household chores has never been more keenly felt, especially with bigger families.
So it is perhaps unsurprising that the latest iteration of the National Science Challenge this year has focused on life hacks to help make chores easier.
A total of six life hacks were put forward by the competition’s champion -- NUS High School of Mathematics and Science -- and two runner-ups: Raffles Institution (RI) and River Valley High School (RVHS).
1. Removing the sticky residue of a label from a surface
We’ve all had that moment when we attempt to remove the stickers off fruits that we have bought, such as apples, only to have the stickers leave behind a residue that doesn’t seem to come off, even when you wash the fruits with water.
This is because water is a polar substance while the residue of stickers is a nonpolar substance, which means that it is unable to dissolve in water.
What it can dissolve in however, is oil, another nonpolar substance.
This means that you can fix this problem by pouring some cooking oil on the small surface of the fruit and wiping it with tissue, to completely remove the residue, assuaging any concerns you might have of accidentally ingesting the stuff.
2. Removing the oil on the surface of soup
Speaking of oil, whenever you have a hotpot meal, you may notice the sizable layer of oil floating at the top of the soup.
If you are concerned about the unhealthiness of the oil layer, you might be pleasantly surprised to know that it can be removed with some pieces of ice.
The oil in the soup is mostly made of saturated fats or fats which are fully hydrogenated. This
means that they are made of long chains of carbon without any double bonds between them, and will therefore freeze into a solid at a much lower temperature compared to water.
So all you need to do is to place the ice on a spoon and dip it into the soup, which will cause the oil to freeze and coagulate onto the ice.
You can then easily remove the solidified oil from the soup.
3. Removing dried permanent ink
Let’s say you wrote down some of your errands on a small whiteboard you keep for such purposes.
Shortly after, you discovered that the marker you used was a permanent marker and it’s now dried and can’t be rubbed off to make way for new appointments.
Fortunately, the marks can be wiped off with rubbing alcohol or hand sanitiser.
If you’re wondering why permanent markers function in such a way, it might be useful to note that permanent ink consists of:
- Resin (the same substance found in printer ink), which makes the ink ‘stick’, due to strong intermolecular forces of the resin molecules, and
- A solvent containing volatile organic compounds (VOCs), such as xylene or ethanol, which dissolves the resin
These compounds evaporate quickly, leaving the resin, which stays permanently on the surface.
As such, the hand sanitiser with its own solvent can ‘attract’ the resin away from the surface, allowing the ink to be rubbed off.
4. Separating pepper from eggs using static electricity
Most of us who like having an egg in the morning have probably found ourselves at one point, having added too much pepper, and were now more or less stuck with eating an egg way too spicy for our liking.
The good thing is, there is actually a solution involving two easily-found items: a cloth and a plastic spoon.
All you need to do is to wipe the spoon with the cloth and place it near the egg. This will cause the pepper to fly out of the egg and stick to the spoon, thanks to the static electricity that has been generated.
Here’s how the whole phenomenon works:
- Originally, the plastic spoon has a neutral charge,
- When the plastic spoon is rubbed with the cloth, the plastic spoon will gain electrons and have a negative charge.
- When the plastic spoon is placed near the pepper mixture, the positively-charged electron groups in the pepper will move towards the spoon while the negatively-charged groups will move to the opposite side, forming a dipole,
- This causes the pepper to be positively-charged at the end nearer to the plastic spoon, and negatively-charged at the other,
- Since opposite electric charges attract, the negatively-charged plastic spoon will attract the positive charges in the pepper grain, causing it to fly out from the egg and stick to the plastic spoon.
And while we are on the topic of eggs:
5. Checking if eggs are fresh
All you have to do is to put the egg in a bowl of water. If it sinks to the bottom, it’s fresh. If it floats, it has gone bad.
The principle here is that chicken eggs have a porous shell to allow the developing chick inside to breathe. So if an egg floats, it means that an air bubble has formed in the egg as a result of escaping water, and that the insides are no longer fresh.
6. Making bananas ripen faster
If you find yourself getting a little annoyed by how many bananas on sale still seem unripened, fret not -- all you have to do is to place them in a plastic bag to make them ripen faster.
This is due to the release of ethylene gas by bananas which is what causes them to ripen in the first place.
So by enclosing the bananas in an airtight plastic bag, the concentration of ethylene gas around the bananas increases, which in turn causes the bananas to ripen faster.
All in all, pretty neat.
Click here to watch the National Science Challenge 2020/2021.
Top image via Pixabay