A student wants to find the total mass of dissolved mineral solids in a 200 cm3 sample of geothermal spring water. She follows these instructions:
Step A: Weigh an empty evaporating basin. Step B: Transfer 40 cm3 of geothermal spring water into the basin using a measuring cylinder. Step C: Heat the basin with a Bunsen burner until all the water has evaporated. Step D: Allow the basin and residue to cool. Step E: Weigh the basin and dry residue.
The student obtains the following results:
State the name of the apparatus used to weigh the evaporating basin and its contents.
Describe one safety precaution the student should take during Step C, and give a reason for this precaution.
Calculate the mass of dissolved mineral solids in the original 200 cm3 sample of geothermal spring water.