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Salts. Table salt, NaCl has been very important for the development of civilization . It was useful as a preservative and helped humans avoid seasonal dependence on food. Allowed us to ship some foods over long distances . Trade routes to transport salt, “ salt roads ” were set up.
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Table salt, NaCl has been very important for the development of civilization. It was useful as a preservative and helped humans avoid seasonal dependence on food. Allowed us to ship some foods over long distances. Trade routes to transport salt, “salt roads” were set up.
Because of its usefulness and difficulty to obtain, it became more precious than gold, like the spices traded along the spice routes. In some areas, people were paid in salt as currency such as in the Roman Empire. Salary, comes from the Latin word for salt which is sal.
Ancient Chinese method of obtaining salt by boiling brine. Saline Veche, Europe’s largest Salt mine, located in Romania.
Salts are a group of ionic compounds. Therefore they are made of a metal and a non-metal. Salts are vital for life. • Cellular communication pathways. • Nerve function and muscle function. Salts can be made in many ways.
Neutralization reaction. Salt and water are made when you mix and an acid and a base together. Ex. HCl + NaOH NaCl + H2O acid base salt water Ex. 3H2SO4 + 2Al(OH)3 Al2(SO4)3 + 6H2O acid base salt water
What did you notice about the reactions? How are the atoms moving?
What did you notice about the reactions? How are the atoms moving? • The atoms swap places. • Ex. H and Na swap places. • H combines with OH to make H2O. • Na combines with Cl to make NaCl. This is called a double replacement reaction.
Acids and Metals Another way to make salts is by a chemical reaction of a metal and an acid. • Hydrogen gas is also released. The best metals for this are the alkali and earth alkaline metals which react easily with acids and water. (First two columns) Other metals need stronger acids to react with.
Ex. 2HCl(aq) + Mg(s) MgCl2(aq) + H2(g) acid metal salt gas Ex. 3H2SO4(aq) + 2Al(s) Al2(SO4)3(aq) + 3H2(g) acid metal salt gas
What did you notice about the reactions? How are the atoms moving?
What did you notice about the reactions? How are the atoms moving? • The atoms swap places. • Ex. Mg and H swap places. • Mg combines with Cl to make MgCl2. • H is left alone and becomes hydrogen gas, H2. This is called a single replacement reaction.
Acids and Carbonates Another way to make a salt is by reacting an acid with a carbonate. Carbonate: A salt with a carbonate ion in it. Ex. H2SO4 + CaCO3 CaSO4 + H2O + CO2 acid carbonate salt water carbon dioxide
Can you predict the outcomes? When you see that each type of these reactions occur in their own special way, can you predict what the products will be? Try Practice Problems p. 236 and 238.