J 5A Molar Volume Lab

Molar volume is the volume occupied by one mole of gas collected at standard temperature and pressure or STP.

Materials NeededEudiometer

400 ml beaker

Ring stand

Buret clamp

Two hole rubber stopper

Copper wire

Chemicals Needed

Magnesium ribbon, 3.5 – 4.0 cm length

6 M Hydrochloric Acid

Read the procedure. Assemble all equipment.

Copper Wire

Magnesium ribbon

Measure the magnesium ribbon.

Magnesium ribbon

Use an analytical balance to get the mass of the magnesium ribbon.

Magnesium

Pour 10 ml of 6M HCl directly into the eudiometer. Use the graduations on eudiometer to measure.

Fill the eudiometer all the way to the brim with distilled water.

Curl the magnesium ribbon and secure to the copper wire.

The magnesium is attached to the copper on the rubber stopper.

Magnesium

Magnesium ribbon

The rubber stopper is placed in the end of the eudiometer.

The eudiometer is inverted in a beaker of water.

Allow the magnesium ribbon and the HCl to react in the eudiometer until the reaction is complete.

Bubbles begin to form at the magnesium ribbon.

Bubbles

Increased Bubbles

As the reaction advances the bubbles become more intense.

Pocket of Gas

As gas forms, the water is pushed out of the eudiometer through the holes in the rubber stopper.

Read the ml

This is the amount of gas that has been collected in the eudiometer.

Place the eudiometer in a large graduated cylinder filled with water.

Keep one finger over the holes in the rubber stopper when placing the eudiometer in the graduated cylinder.

Level inside tube

Level inside cylinder

Make the water level inside tube be on the same level as the water level in the graduated cylinder.

The two levels are the same for the final reading.

Final reading for the volume of the gas in the eudiometer.

Final reading

Read the barometric pressure

Mercury level

700 mmHg

800 mmHg

Level of mercury

700 mmHg

54 mmHg

Take the reading on the thermometer.

Final CalculationsRead the volume of the gas collected in the eudiometer and record in the data table.

Record the barometric pressure.

Record the room temperature.

Determine the water vapor pressure using a water vapor pressure table.