The purpose of this experiment was to determine the percent of chlorine in an unknown soluble salt through using gravimetric techniques. The unknown salt was dissolved in water and the chloride ions were precipitated using silver nitrate which produced silver chloride. The silver chloride was then separated by filtration techniques and through this the amount of chlorine in the original salt was able to be calculated. It is expected that the chlorine percent will be around 55.95% because that is the accepted value of chlorine content in the unknown salt.
Theory:
In this experiment the unknown salt was precipitated as silver chloride through the addition of silver nitrate. This was done so that the chlorine ions could be separated from the salt to determine the overall percent content. Silver nitrate is used as the precipitating agent because it is highly …show more content…
Silver has an atomic mass of 107.9g whereas sodium has an atomic mass of 22.99g. The mass plays an important role in the value of chlorine because the mass precipitate value is used to determine the amount of chlorine moles in the precipitate. If the overall precipitate weighs less, there will be less moles of chlorine because there is less of the overall precipitate.
Another ion that can co-precipitate with a chlorine ion is Mercury and it will have a higher value than silver chloride. This is because mercury weighs more than silver, so the overall mass of the precipitate will be greater. Silver has an atomic mass of 107.9g, whereas mercury has an atomic mass of 200.6g. Mercury has two valence electrons and chlorine has seven valence electrons. Therefore for a reaction to occur, chlorine steals one of mercury's electrons to fill its orbital making it a stable ion. The following reaction is as followed:
[6]
Hg+(aq) + Cl- (aq) ——>