Put a known volume of water into a boiling tube. Add soap solution, one drop at a time, and shake the mixture for 10 seconds. Record the number of drops of soap needed to make a lather. The ...

Sodium carbonate, Na 2 CO 3, is also known as washing soda. It can soften water that has temporary hardness and it can soften water that has permanent hardness. It is an inexpensive method of ...