Chemistry

2019-12-31 (Réveillon!)

Posted on by What did you learn in School today ?

Today, I learned about:

Once again, it is that day of the year when we reflect over how the year behind us was and make our predictions and wishes for the year to come.

One important piece of news during 2019 was that researchers at my alma mater Chalmers University of Technology, Gothenburg, Sweden, led by professor Kasper Moth-Poulsen reported that they have developed a molecule, that is able to capture the sun’s rays, store it as chemical energy for up to 18 years, and retrieve the energy and convert it into heat when needed.

The following graphic shows how it all works:

It all starts in the upper middle section of the sketch. The solar reflector (SOLFÅNGARE) placed on the roof of a building captures the sun’s rays. The parabolic section concentrates solar energy and transmits it to the liquid in the tube in the center of the solar reflector. From there, the cold liquid, now containing stored chemical energy, is sent to an energy storage (ENERGILAGER). It can be stored there for up to 18 years! When we need to heat up our house, we simply let some of the liquid out from storage, run it through the catalyst (KATALYSATOR), thus obtaining a hot liquid without any stored chemical energy. Experiments have shown that the liquid with released heat can have a temperature that is 63 °C higher after the catalyst in relation to before! The hot liquid then goes into the normal heating system of the house, e.g. the radiators (ELEMENT I HUS) in the various rooms, heats up the ambient, and then the now cold liquid goes back up to the roof to capture more sun rays. Graphic made by Yen Strandqvist.
The leftmost photo shows the parabolic solar reflector with the liquid tube in the center. To the right is the inventor of the material, professor Kasper Moth-Poulsen, securing a small sample of the miraculous liquid. All material has been extracted from Chalmers Magasin no. 1 2019, text by Karin Aase and photos taken by Oscar Mattsson and Johan Bodell.

References # 1 through 4 below contain more material if you are interested in further details.

Can you use an hourglass?

According to Wikipedia: “An hourglass (or sandglass, sand timer, sand clock or egg timer) is a device used to measure the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) from the upper bulb to the lower one. Typically the upper and lower bulbs are symmetric so that the hourglass will measure the same duration regardless of orientation. The specific duration of time a given hourglass measures is determined by factors including the quantity and coarseness of the particulate matter, the bulb size, and the neck width.

So you think are smart? Then show it now! We have two hourglasses like the ones shown above. The bigger ones completes one cycle in 11 minutes, the small one in 7 minutes.

Question: Using a combination of these two hourglasses, you need to measure a time lapse of exactly 15 minutes. How would you do it? (Solution to follow in the first blog post of 2020.)

I wish all my faithful blog readers a HAPPY NEW YEAR!

That’s what I learned in school !

Refs.:

1: Extract from Chalmers Magasin nr 1 2019 (article in Swedish)

2: An energy breakthrough could store solar power for decades

3: Storing the energy from the sun for decades

4: Liquid sunlight creates heat on demand

*: What did you learn in school today ?

2019-03-05 (É carnaval!)

Posted on by What did you learn in School today ?

Today, I learned that:

As you probably have heard, one of the most important events during the year in Brazil is to commemorate carnival. For a complete description of what carnival is, I recommend that you consult reference #1 below.

The most important day during carnival is always on the final Tuesday, and this year it occurs very late, March 5. Normally it is in February, but from time to time it can be in March. I thought that March 5 would be the latest possible date for carnival Tuesday, but in order to be sure, I consulted an authority in the matter, a well known German-Swedish meteorologist named André Franke. If you live in Sweden, then you have probably seen and heard him on the weather forecasts. Here is what he told me:

Carnival Tuesday occurs 47 days before Easter Sunday and thus varies in the same way as Easter. This year Easter Sunday is April 21 and as consequence, Carnival Tuesday is on March 5. Next time this will happen is in year 2030.

However, the latest date that Easter Sunday can occur is on April 25, which will happen in year 2038. Carnival Tuesday will then be on March 9, 2038. Recently, in year 2011, it almost happened, Easter Sunday was on April 24 and Carnival Tuesday on March 8. All this is due to when the March Equinox occurs. Easter Sunday is the first Sunday after the first full moon on or after the March Equinox.

The Equinox, which is a point in time, can occur on different dates on different places of the Earth, due to the time zones, but Easter Sunday is on the same date all over the globe, and as a consequence also the Carnival Tuesday.

André also has his blog, see reference #2 below, where he details various astronomical facts occurring over the year. If that sounds interesting to you, then I definitely recommend that you look it up, it is well worth it!

The periodic table 150 years

Anyone who remembers their Chemistry lessons will surely also remember the periodic table. This table is an elegant composition of the different elements present in our universe. It was proposed by the Russian chemist Dmitri Mendeleev and first presented to the world on March 6, 1869.

Thanks to his way of organising the elements in a systematic manner, many new elements which only appeared as blanks in his original table were soon discovered and his forecasts about their properties were surprisingly exact. See also reference #3 below.

That’s what I learned in school !

Refs.:

1: Carnival

2: Astroinfo.se

3: Dmitri Mendeleev

*: What did you learn in school today ?

2016-01-14 (Thursday)

Posted on by What did you learn in School today ?

Today, I learned that:

There is something new in the world of chemistry, and although I am not very fond of chemistry, this is really thrilling. IUPAC (The International Union of Pure and Applied Chemistry), announced that four new elements of the periodic table (elements 113, 115, 117, and 118) have been discovered and approved. These elements complete the 7th row of the periodic table of the elements, and the discoverers from Japan, Russia, and the USA will now be invited to suggest permanent names and symbols.

IUPAC_Periodic_Table-8Jan16

The current Periodic Table of the Elements, Copyright © 2016 IUPAC, the International Union of Pure and Applied Chemistry

Also, in the same podcast, The Naked Scientists, where these new elements were discussed, they talked about how the physicists Max von Laue and James Franck, who had won the Nobel Prize in 1914 and 1925, respectively, were able to save their golden medals from falling into Nazi hands during World War II. Their colleague George de Hevesy hid their medals in a bottle in a lab at the Niels Bohr Institute and dissolved them in aqua regia, a concentrated nitrogen hydrochloric acid (‘kungsvatten’ in Swedish). After the war, the gold solution was still there, and then it was transformed back into solid gold and recast to medals by the Nobel authorities in Stockholm. Finally, the scientists received their Nobel medals back.

… That’s what I learned in school!

Refs.:

1: 04:33 – Four new elements discovered

2: Discovery and Assignment of Elements with Atomic Numbers 113, 115, 117 and 118

3: Aqua regia

+: What did you learn in school today ?