If your determination of the mass of the sand in the vial was +/- 0.006 g ( +/- 0.2%), good job, you did well. Most of you noticed that there were fine sand particles adhering to the side of the vial. In order to determine the mass of the sand accurately, here are the steps to consider.

1. Weigh vial with the sand on the balance.
2. Empty the sand into another container.
3. Rinse the vial with water thoroughly.
4. Dry the vial thoroughly.
5. Reweigh the empty vial.
6. Subtract the mass from step 5 from step 1 to get the mass of the sand.

It is not always necessary to transfer the sand into a weigh boat in order to determine its mass. Leaving the sand in the vial will eliminate the loss of sand during the transfer.

Now that you know how to weigh properly, you need to apply the techniques learned for next week’s lab because next week is all about weighing.