Essentials of Geology (Geol 1030)
Laboratory #4-Chemical Weathering & Surface Area
Materials for each group:
2 600 ml glass beakers with rock fragments
1 Strainer
1 flask of 100 ml of 10% HCL
1 laboratory balance
lots of water & paper towels
Procedure:
1 Rinse the rock chips in each jar with clean water to remove any dust or loose
grains. Let water run slowly into each jar until ¾ full and then drain the water,
including the samples, into the strainer. Repeat several times for each beaker and
then let the rock chips and beaker dry on paper towels for a minute or two.
2 Next, place the rock fragments on weighing paper or a weigh boat and use a
laboratory balance to find the mass of the rock fragments (to the nearest gram).
Record the information in Data Table #1.
3 Place the rock fragments back into the beaker. Using the flask provided, pour the
10% HCL over the rock fragments. This amount of liquid should completely
cover the rock chips. Set the beaker aside for at least one day.
** SAFETY NOTE! Avoid getting this solution on your body or
clothes. Should this occur, inform your instructor and rinse with
plenty of fresh water! Follow the procedures outlined by your
instructor for proper handling of glassware, the mass balance, and
acidic liquids.
4 On the next day of this activity, pour off the acid solution from each jar. Use the
strainer to catch any rock fragments which may fall out. You may pour the acid
solution down the drain, but flush with plenty of fresh water.
5 Rinse the contents of the strainer and then return them to the beaker. Repeat steps
1,2 & 3.
6 Continue this daily procedure for each of the days as directed by your instructor.
Make sure you record your results in the Data Table on the following page.
