Discussion: At each lab station is a sample of a different element. The number of moles of the substance can be found on the card at the station. The mole is a very important unit of measurement in chemistry. In this lab you will learn how the mass of the element if related to this unit.
When your teacher tells you to begin, go to one of the lab stations. It does not matter where you begin as long as you go to all of the stations. Determine the mass of the element with its container. Record this value. To save you time, the mass of the container is recorded on the card at the station. Find the mass of the element. Find the mass of one mole of the element. For some of the elements you have exactly 6.02 x 1023 atoms, or one mole, so this calculation is already done. Once you have calculated the mass of one mole, refer to your periodic table to find the identity of the element. Before you leave the station, be sure to write a brief physical description of the element. Chemists often identify elements from their physical properties. As always, rezero the balance before leaving the lab station.
Good luck in learning the identities of the elements. May the mole be with you!
Period Name
Please record your measurements and calculations to the correct degree of accuracy.
Lab Station
Description of element
Mass of element + container
Mass of container
Mass of element
Moles of element
Mass of element / mole
Identity of element
Post Lab Questions
1. Which element did you know by its physical properties?
3. Which element do you learn what it looks like?
3. Do you think that you have identified any of the elements incorrectly? Which and why?
Editor's Notes:
This activity was sent to me with no directions. However, it seems like a good classroom activity. It looks to me like the teacher will have to set up several lab stations with a known mass of some element present in a beaker for the student to work with. For example, a station could contain 32.46 G of Mg in a beaker. The goal of the exercise seems to be the identification of the unknown element by comparing the calculated mass per mol with the atomic weight of the element. Therefore, the number of atoms of element must be given to the student at the station.
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