Week 7: Molecular Weight

Alkali Earth metal of the week: Magnesium

Magnesium is an alkali Earth metal with an atomic number of 12 and an atomic weight of 24.3050, which is abbreviated by the letters Mg. Magnesium is the fourth most abundant element on Earth, comprising a whopping 13% of Earth’ mass. Magnesium is easily built in supernova stars and is highly water soluble, which makes it the third most common element dissolved in seawater. Magnesium is the 11^th most common element in the human body, where it manipulates DNA, RNA, and ATP. Mg is crucial the function of living cells. It is also found in chlorophyll and is used medicinally as laxatives, antacid, and many conditions where calming nerves or blood vessel spasms is required.

Avogadro’s hypothesis

Avogadro’s hypothesis was that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. He also made a distinction between atoms and molecules and said that atoms of the same element could combine, which contradicted scientist John Dalton’s beliefs. Although these statements are widely accepted by the scientific community now, they were not taken seriously when Avogadro made these findings because his work was in an obscure publication and also contradicted the opinions of John Dalton, who was a well-respected scientist of Avogadro’s era. Shortly after Stanislao Cannizaro explained Avogadro’s principles in “Sketch of a Course of Chemical Philosophy,” Avogadro finally received the acclaim his hypotheses deserved. Avogadro’s hypothesis led future scientists to determine Avogadro’s number, which was based on Avogadro’s basic hypothesis.

What is a mole?

It was show that a Gram Molecular Weight of gas at standard temperature and pressure occupies 22.4 liters of volume. A mole is the number of molecules contained in 22.4 liters of a gas at standard temperature and pressure. The benefit of the “mole” concept is that it allows the scientist to relate the weight of the material to the number of molecules in that weight, which is a ridiculously large amount that could not be counted under a microscope or any easy quantitative measure. Avogadro’s number- which expresses this ridiculously large amount- is 6.0221367 x 10 exp23- and is the number of molecules in 22.4 liters of gas at standard temperature and pressure.