Topic 3: Lesson 1 Video 1: - a great variety of soluble minerals that are dissolved in the ocean. Example: a 60-milliliter sample of water taken from the shores of New Jersey, sitting on a hot plate. As we slowly evaporate the water from the heat generated by the hot plate, it boils down to amount of mineral material. - The percentage by weight turned out to be 3.5%, - exactly what is thought to be the amount of mineral material or salt material that's dissolved in most of the oceans of the world. This is not the case in every part of the ocean system of the planet. - Galapagos: 10% more than was in the sample off the coast of New Jersey because there's very little fresh water that flows out of the Galapagos Islands and it's warmer all year long. - The percentage of salt materials that are in the Dead Sea runs around 30%. It varies during the year and fluctuates. Video 2: - elements that are involved in salts: sodium, potassium, magnesium, chlorine - have to differentiate between an element and salt itself. The representations for calcium, magnesium and sodium. - Ca++ - Mg++ - Na+ They have outer electrons that can be quite easily removed. Calcium and magnesium have 2 plus and sodium has 1 plus. They combine with a variety of negatively charged ones, such as bicarbonate (HCO3), chloride (Cl-), and sulfate (SO). There is also bromide, and on the other side, there is potassium as a K plus salt-- or ion. Essentially, all of the combinations are possible. If we just isolate calcium and sulfate the charges will balance. - Ca++ and SO4 = amounts to the mineral Gypsum , which is white in powdered form. - Mg++ and SO4 = magnesium sulphate - Epsom salts - Calcium combination with bicarbonate-- the HCO3 minus. This clearly requires two of the negative charges. But that molecule decomposes quite readily into calcium carbonate (CaCO3), carbon dioxide, and water. The calcium carbonate that is deposited-- that's essentially limestone . - Table salt clearly is sodium chloride. However, in nature, the combinations are quite varied. As an example, dolomite -- which is a mineral of a mixture of calcium carbonate and magnesium carbonate often co-crystallizes with other minerals Cinnabar , or mercury sulfide , is present in calcium carbonate and magnesium carbonate and it was for years used as vermilion, which is a paint pigment.
However, in health food stores it's possible to buy what can be called dolomite, which is indeed a source of magnesium and calcium minerals as a supplement possibility.
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- Spring '11
- Sodium, Sodium chloride