lunes, 22 de octubre de 2012

Happy mole day!

Tomorrow, October 23rd, we will celebrate the "Mole day", starting at 6.02 AM till 6.02 PM. This celebration relates to Avogadro's number which is approximately 6.02 x 1023. The National Mole Day Foundation organizes activities for this day. The theme for this year is the Molar Eclipse.
Below, you have a video "A mole is a unit". I hope you will enjoy it.



Happy mole day to you!

domingo, 2 de septiembre de 2012

Homenaje al Dr. Tirso Rios

On September 3rd it will take place an act in honor to Dr Tirso Rios, recently deceased on June 18th, at “Instituto de Química” from UNAM (Universidad Nacional Autónoma de México).

martes, 21 de febrero de 2012

King cakes

The origin of kings’ cake dates from the roman times, and it was not a religious tradition. The cake was served at Saturnalia celebrations (Slaves festivity) in December. It was a commemoration of the renewal of light and the end of the labor in the countryside. At that time the peasants and the slaves had the opportunity to rest and recover from the efforts realized during months. In order to celebrate it, they prepared round cakes, which included figs, dates and honey, and distributed them as a gift for the work well done.
In the III century a dry bean was introduced inside the cakes. It was a symbol of prosperity, and the one that found it would be named “king of kings” during a certain time previously established.
It was in the IV century when the Church converted the festivities in Christian celebrations.
It was in France where they started to celebrate “Le Roi de la Fave” (The king of the bean). Children were the protagonists, and the one that found the bean in the cake was treated with gifts and pampered by everyone on the 6th of January.
Actually in Spain it is a tradition to have kings’ cake (Roscón de Reyes) during the Magic Kings day on the 6th of January, where the Christmas festivities end. Nowadays you can find a bean and a plastic baby or a similar figure. The one that gets the bean has to pay the cake and the one that gets the baby will have good luck.
In South Louisiana it is a tradition to have king cake for Mardi Gras. From the day after Kings Day until Ash Wednesday you can find king cakes in the bakeries, some of them have their own special recipes. These king cakes are decorated with the traditional Mardi Gras colors: purple, green and gold. Inside every king cake a plastic baby is hidden. The tradition is that each person takes a piece of cake, and the one that finds the plastic baby inside is obligated to host the next king cake party and supply the king cake.
It is probable that the New Orleans king cake evolved from the customs of old South Louisiana’s immigrants. In the Picayune cookbook says that New Orleanians started serving king cake as part of the Spanish celebration of King’s Day. However other food historians believe that the New Orleans king cake was really an Italian or a French tradition.
Here you will find an easy recipe of a king cake from Stephanie Gallagher The Iron Chef Mom.
Next, you can also find a recipe of kings’ cake (Roscón de Reyes) that was broadcasted by RTVE as part of the program “La mañana” on December 29, 2011.
I hope you are able to make both cakes and compare them. Happy Mardi Gras!


martes, 14 de febrero de 2012

Happy Valentine's day

As a Valentine’s day gift I propose you to watch a video from the University of Leicester Department of Chemistry where you can see three experiments somehow related to love. The first one is called “Love chemistry” and emulates a heart where a colorless compound [(NH4)SCN] is added to a yellow compound (FeCl3) to yield two products with a blood red color. The second one is called “The thunder storm” where ethanol, sulphuric acid and potassium permanganate are mixed together in a beaker to react like a storm with some lightning. The third one is called “Mercury beating heart” in which a few drops of mercury are placed in a watch glass and some sodium thiosulphate and potassium dichromate are added around the mercury. When an iron nail touches the mercury, it looks like a heart beating. It is pure electrochemistry! I hope you will enjoy them.



domingo, 5 de febrero de 2012

Daniel Radcliffe sings "The elements"



Tom Lehrer was born April 9, 1928. He earned a Bachelor (1946) and a Master (1947) in Mathematics at Harvard. He remained at Harvard as a graduate student until 1953. During this time, he wrote "The Physics Revue", a collection of academic song parodies and among them is "The elements".


In a TV Show "The Graham Norton Show" at BBC, Harry Potter star Daniel Radcliffe performs "The elements". I hope you enjoy the sketch.

domingo, 22 de enero de 2012

Stoichiometry rules

Here you have a song by Mark Rosengarten, that explains how to convert among grams, liters of ideal gas at STP and number of molecules via their common factor: moles. I hope it will help you to do the stoichiometry problems.