Determination of the molar mass of magnesium
by
k296 (student)
Kamil Kamiński
IB2
02/12-12
Determination of the molar mass of magnesium
Introduction:
This experiment will be an attempt to determine the molar mass of magnesium. For that we will have an experiment where we dissolve sulphur into hydrochloric acid. Then we measure the amount of gas created during the reaction. To get the molar mass itself we will have to make sure to record the conditions of the experiment such as the temperature or pressure.
Material:
The material used for the experiment was:
- eudiometer
- thermometer
- barometer
- measuring cylinder (1000 cm3)
- Stand with clamp
- magnesium ribbon
- hydrochloric acid
Method:
- About 20mm of magnesium ribbon and weight it with the accuracy of 0.001g
- Pour 5cm3 of HCl into the eudiometer. Then carefully filling the eudiometer with water above the HCl, without mixing the liquids.
- Wind the magnesium ribbon around a piece of copper wire and let it hang down a little bit into the eudiometer. Make sure there is a hole into the rubber stopper and fill it with water.
- Place a large measuring cylinder filled with water in the sink. Put a finger over the hole in the stopper and turn the eudiometer upside down into the cylinder.
- Observe what happens with the hydrochloric acid and magnesium after a little while. When the reaction is complete wait at least 5 minutes so that the eudiometer reaches room temperature.
- Arrange the eudiometer in the cylinder so that the gas into the eudiometer has the same pressure as the air pressure in the room. Note the air pressure and temperature in the room.
- Calculate the molar mass of magnesium.