Computation In Solving Weight

Counting by Measuring Mass

Purpose

Determine the mass of several samples of chemical elements and compounds and use the data to count atoms.

Procedure

Start Virtual ChemLab and select Counting by Measuring Mass from the list of assignments. The lab will open in the Calorimetry laboratory.


Part 1, Measuring Metal

1. Click on the Stockroom. Click on the Metals sample cabinet. Open the top drawer by clicking on it. When you open the drawer, a petri dish will show up on the counter. Place the sample of gold (Au) in the sample dish by double-clicking on it Zoom Out. Double-click on the petri dish to move it to the stockroom counter. Click the green arrow to Return to Lab.
2. Drag the petri dish to the spotlight near the balance. Click on the Balance area to zoom in. Drag the gold sample to the balance pan and record the mass in Table 1.
3. Click on the red disposal bucket to clear the lab after each sample. Repeat for lead (Pb), uranium (U), sodium (Na) and a metal of your choosing.

Table 1
|                         |gold (Au)             |lead (Pb)               |uranium (U)             |sodium (Na)             |Your Choice             |
|Mass                     |                       |                       |                       |                       |                       |
|(grams)                 |                       |                       |                       |                       |                       |
|Molar Mass (g/mol)       |                       |                       |                       |                       |                       |
|Moles of each element   |                       |                       |                       |                       |                       |
|Atoms of each element   |                       |                       |                       |                       |                       |







Analysis

1. Calculate the moles of Au contained in the sample and enter...