Title: Accurate Measurement of Mass and Volume
Part A: The Formula of Hydrated Copper (II) Sulfate
Aim: The objective of this experiment is to find out the accurate mass of a solid and to calculate the moles of an unknown.
The materials used in this experiment are Hydrated Copper (II) Sulfate, weighing bottle, analytical balance, laboratory balance, casserole, spatula, and hotplate.
First, approximate 1.0g of hydrated copper (II) sulfate was transferred into a weighing bottle and the lid was screwed on. The colour of the solid was noted.The capped bottle was then taken into the analytical room and its mass was accurately measured. Then, the copper (II) sulfate was transferred from the bottle into a casserole. The empty bottle with lid was reweighed using the analytical balance. The purpose of this procedure is to accurately determine the mass of copper (II) sulfate and to eliminate the risk of spilling chemicals in the analytical room. After that, the casserole dish was heated using a hotplate until the powder turns into pale blue colour. It is advised not to heat it strongly to prevent it to start blacken. For normal case, a settling of 3-4 for about 20-25 minutes should provide sufficient heating. Next, the crucible was removed from the hotplate and allowed to cool for around 2-3 minutes. The contents was then transferred back into the weighing bottle and recapped. The solid was made sure to be transferred as much as possible into the weighing bottle as the mass would have direct bearing on the calculations. The capped weighing bottle which now contains dehydrated copper (II) sulfate was accurately weighted. Finally, the copper (II) sulfate was disposed into the waste container in fume hood. The results are tabulated under Table 1.0 below. Results:
Table 1.0 Mass and Moles of Copper (II) Sulfate
Mass of capped weighing bottle + hydrated (blue) copper (II) sulfate| 42.3883g| Mass of empty (capped)...