Barrons SAT Subject Test Chemistry, 13th Edition

Figure 41. Eudiometer Apparatus

Example

Measure the mass of a strip of magnesium with an analytical balance to the
nearest 0.001g. Using a coiled strip with a mass of about 0.040g produces about
40mL of H 2. Pour 5mL of concentrated HCl into a eudiometer, and slowly fill the

remainder with water. Try to minimize mixing. Lower the coil of Mg strip into the
tube, invert it, and lower it to the bottom of the beaker. After the reaction is
complete, you can measure the volume of the gas released and calculate the mass
of hydrogen replaced by the magnesium. (Refer to Chapter 5 for a discussion of
gas laws.)

SUMMARY OF QUALITATIVE TESTS

I. Identification of Some Common Gases

Gas

Test

Result

Ammonia

NH 3

1. Smell cautiously.
   
   
   1. Sharp odor.
   
   
   
   


2. Test with litmus.
   2. Red litmus turns blue.


3. Expose to HCl fumes.
   3. White fumes form, NH 4 Cl.

Carbon

dioxide

CO 2

1. Pass through limewater, Ca(OH) 2.
   
   
   1. White precipitate forms, CaCO 3.
   
   
   
   

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