Why lattice anergy is the key to the formation of salt?

Answer 1

Lattice energy is the energy given off when oppositely charged ions in the gas phase come together to form a solid. This process releases a great deal of energy. Table Lattice energy is the energy given off when oppositely charged ions in the gas phase come together to form a solid. This process releases a great deal of energy. Table salt is made up of chloride and sodium. The ions of each element bond together to create the compound know as salt, or sodium chloride. The opposite charges of the ions of each force the atoms together. The lattice energy is what causes the salt to crystallize when the two elements from the compound. The importance of lattice energy is that it prevents the compound NaCl (table salt) from being NaCl2, or NaCl3, etc salt is made up of chloride and sodium. The ions of each element bond together to create the compound know as salt, or sodium chloride. The opposite charges of the ions of each force the atoms together. The lattice energy is what causes the salt to crystallize when the two elements from the compound. The importance of lattice energy is that it prevents the compound NaCl (table salt) from being NaCl2, or NaCl3, etc

Answer 2

The lattice energy is defined to be the energy you get out when you take gaseous ions and from an ionic lattice out of them. To see why a big lattice energy is necessary to form a salt you need to ask yourself what it takes to form an ionic compound. So take a metal like sodium and a non-metal like chlorine. 1. You need to turn Na(s) into Na(g). This take 108 kJ/mol of sodium to do this. 2. You have to pull the electron off of the sodium. Contrary to popular belief, Na does NOT want to give up an electron. It takes 496 kJ/mole of energy to remove electrons from sodium. 3. You need to break the bond between the two chlorine atoms in Cl2. This requires about 120 kJ/mol of chlorine atoms produced. 4. You need to put an electron on the chlorine. This is actually a favorable process---the energy you get out is the electron affinity, which is -350 kJ/mol. So at the moment we are around 380 kJ/mol in the hole. So why does all this still happen? Because when you take a mole of Na+ ions and a mole of Cl- ions and put them in a lattice where there are multiple contacts between positive and negative ions you get a TON of energy out... -787 kJ/mol for NaCl. That is why a high lattice energy is the key to salt formation---if you did not get a lot of energy out of the many electrostatic attractions you form in the lattice you could not accomplish all the things above that it took to form the ions.