I tested the conductivity for two salts (NaCl and MgCl2) and I noticed that Nacl conducted more electricity. Why?

The difference in conductivity between NaCl and MgCl2 can be attributed to the presence of different ions in each salt solution. To understand why NaCl conducted more electricity than MgCl2, we need to consider the nature of the ions present and their ability to carry electric charges.

When NaCl is dissolved in water, it dissociates into two types of ions: sodium (Na+) and chloride (Cl-) ions. These ions are free to move in the solution and carry electric charges. Sodium is a monovalent cation, meaning it carries a single positive charge, while chloride is a monovalent anion, carrying a single negative charge. Since both types of ions are singly charged, they are highly mobile and can easily carry electric current. As a result, NaCl has good conductivity.

On the other hand, when MgCl2 is dissolved in water, it dissociates into magnesium (Mg2+) and chloride (Cl-) ions. Magnesium is a divalent cation, meaning it carries a double positive charge, while chloride is a monovalent anion, carrying a single negative charge. The presence of divalent magnesium ions leads to their stronger attraction to water molecules, reducing their mobility in the solution. This reduced mobility of the magnesium ions decreases the conductivity of the solution compared to NaCl.

In summary, the difference in conductivity between NaCl and MgCl2 can be explained by the presence of different ions and their charges in the solution. NaCl, consisting of singly charged sodium and chloride ions, has higher conductivity compared to MgCl2, which contains doubly charged magnesium ions that are less mobile in the solution.