Which box contains water? Which box contains ice?

Box 1 GIF___ Box 2 GIF

Box 1 VRML Box 2 VRML

The structures you will be using in this experiment were created using molecular modeling software at the the NYU/ACF Scientific Visualization Center.

Problem

To calculate the density for water and ice using molecular structures.

Procedure

1) Review your notes on density.

2) Copy Table II (see Results Section) into your lab notebook.

Shown below are three views (front, top and side) for each of the two boxes.

BOX 1

front top side

BOX 2

front top side

3) Count (estimate) the number of water molecules in the box 1(ice), by using the three views shown. Record your results in Table II

4) Count (estimate) the number of water molecules in the box 2 (liquid water). Record your results in Table II.

5) Calculate the volume of the water box cubic cm. (Note:The side of each box is 10 Angstroms.) Record your results in Table II. 6) Calculate the volume of the ice box in cubic cm.. Record your results in Table II.

7) Find the mass of a single water molecule (in gms.). If you know how to find the mass of a water molecule these pages will be of help

8) Complete Table II.

Results

Discussion

Which box contains water? Which box contains ice? Explain your reasons.

How does the density value for water and ice in Table II compare with those from Table I (part I)? Give reasons for the differences.

Go to Part III

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