Gravimetric Analysis

  1. 01 Prepare
  2. 02 Precipitate
  3. 03 Separate
  4. 04 Dry & weigh
GRAVIMETRY BENCHUnknown AREADY TO PREPARE
Laboratory equipmentA balance, crucible on a clay triangle above a Bunsen burner, desiccator, reaction beaker, vacuum filtration flask and drying oven. 105 °CDRYING OVEN 0.000 gANALYTICAL BALANCE M₂CO₃400 mL BEAKER BÜCHNER VACUUM FILTRATION CaCl₂0.200 M125 mL WATCH GLASS CRUCIBLE TONGS Clean equipment is ready. Begin by drying the empty crucible.
ANALYTICAL BALANCE LIVE READING · ±0.001 g0.000 g
● Goggles on · Handle hot glassware with tongsAccelerated lab time
About this simulation

Based on U6.A2: Gravimetric Analysis of a Metal Carbonate. Equipment is illustrated to resemble real laboratory apparatus. Heating, cooling, filtration, and overnight settling are accelerated; temperatures and timings are procedural targets, not a heat-transfer model. The model assumes quantitative reaction and recovery after three washes. A 2.000 g sodium or potassium carbonate sample reacts with 125 mL of 0.200 M calcium chloride (excess). Lithium carbonate is excluded because its limited solubility makes complete dissolution in 200 mL water unreliable under these conditions. Residual moisture makes the first precipitate weighing too high; repeat drying until the mass is constant. The watch glass is excluded from the filter-paper-plus-solid balance measurement. No student data is recorded or stored.

How to use this lab

Follow the action button to work through the original lab procedure. Observe equipment and balance readings as you go. Use your own lab handout if you need to record measurements.

  1. Dry and cool a clean crucible. Weigh it, add about 2 g of unknown, then heat, cool, and weigh again.
  2. Dissolve the sample in 200 mL deionized water. Add 125 mL of 0.200 M CaCl₂ and allow the precipitate to settle overnight.
  3. Weigh dry filter paper, assemble and wet the Büchner funnel, then decant, transfer, rinse the beaker, and wash the solid three times.
  4. Dry on a watch glass for 15 minutes, break up the solid, and dry for 5 more minutes. Cool before weighing. Repeat the drying and weighing until two readings agree.

Wear goggles in a real lab. Calcium chloride can irritate eyes; avoid dust and contact. Use tongs or a hot-vessel gripper and let hot objects cool in a desiccator before weighing. Heating and cooling here take only a few seconds.

Identify the unknown: one mole of M₂CO₃ forms one mole of CaCO₃. Use 100.09 g/mol for calcium carbonate. Compare the experimental carbonate molar mass with Li₂CO₃ (73.89), Na₂CO₃ (105.99), and K₂CO₃ (138.21 g/mol).