EXPERIMENTAL INVESTIGATION 37.2 How can we investigate if rocks contain carbon?
Equipment Distilled water Beakers Selection of small pebbles and rocks Dropper
Method 1. Rinse all the glassware with distilled water. 2. Place a small pebble or rock in a beaker. 3. Use a dropper to add 3 cm3
of hydrochloric acid to the surface of the small pebble or rock.
4. Add another small pebble or rock of roughly the same mass and surface area to another beaker. Use a dropper to add 3 cm3
of distilled water to the pebble or rock.
5. Observe any chemical reactions that may take place on both of the small pebbles or rocks. If possible, use a hand lens to view the chemical reaction more closely.
6. Record the extent of the ‘fizziness’ of the chemical reactions on a scale from 0 to 5, where 0 indicates no reaction (no fizziness) and 5 indicates extremely reactive (lots of fizziness).
7. Record your observations. 8. Follow steps 2–7 for a wide range of small pebbles or rocks.
Dropper (hydrochloric acid)
1 M hydrochloric acid solution Mass balance Hand lens
SAFETY • Wear gloves when handling the acid, as it is corrosive.
Dropper (distilled water)
Rock :Fig. 37.10 To investigate if rocks contain carbon j Go to page 111 of your Experimental Investigations Log to write up this investigation.