Chemistry

  Lesson 2: Absolute Monarchies Lesson Objectives: Students should be able to: 1) identify the two countries Saudi Arabia and Oman as absolute monarchies 2) identify some characteristics of the two countries and their leaders   1. Who rules the country if it were an absolute monarchy? (King or Queen) 2. Are all Arab countries absolute monarchies? (No, others are republics or constitutional monarchies) 3. Can you give two examples of Arab absolute monarchies? (Oman and Saudi Arabia)   Explain that the first map is the map of Oman. Its flag is shown next to the map (remind students that each country has its own flag to represent it). The capital city (the main city where the king or president of the country usually lives) of Oman is Muscat.   The second map on this page is the map of Saudi Arabia. Its flag is shown next to the map. The capital city of Saudi Arabia is Riyadh. Explain that these two countries are Arab countries, and they a...

What is Brine? How we get common salt present underground. Brine: Solution of NaCl is called Brine. Ø Common salt is obtained from the ground by pumping out in the form of Brine (salt solution). Ø Hot water is pumped down the outer pipe. It dissolves the salt. The salt solution is then forced up the smaller inner pipe by the pressure of water. Ø The brine gets stored in lakes until it is needed. It is then pumped straight to the chemical plant. Brine (salt solution) The second way that we can get salt from the ground is solution mining. This method relies on salt dissolving in water. Look at the diagram below: Brine chemical plant It dissolves the salt. The salt solution is then forced up the smaller, inner pipe by the pr essure of water. The salt solution is called brine. The brine gets stored in lakes until it is needed. It is then pumped straight to the chemical plant. The holes left under the ground must be filled. If not the land above con colla...

  Removing hardness You have now seen how hard water is formed. The calcium or magnesium in the water is present as charged particles called ions. The most common cause of hardness is the calcium ion, Ca + (aq).   These calcium ions react with ions from soap (sodium stearate) to form scum calcium ions (aq) + stearate ions (aq) hard water calcium stearate (s) soap scum If we can remove these Ca* ions from the water we will get rid of the hardness.   Temporary hardness Do you remember how calcium ions from insoluble calcium carbonate get into hard water? Limestone reacts with acidic rainwater. It forms a solution of calcium ions and hydrogencarbonate ions. This is called temporary hardness. When this solution is boiled, the calcium and hydrogencarbonate ions react. They turn back into the insoluble calcium carbonate. Therefore calcium ions are removed from the water.     c...