Loss of mass sim
50 cm³ of hydrochloric acid is in the flask on the balance.
Loss of mass · covers the GCSE, IGCSE, O-Level topic
What the sim shows
50 cm³ of hydrochloric acid is in the flask on the balance. Tip in 6.00 g of marble chips, plug the neck with cotton wool and start the stopwatch. CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂. The carbon dioxide escapes, so the reading falls; the cotton wool lets the gas out but stops acid spray, which would be counted as lost gas. The marble is in excess, so the acid runs out first: twice the acid gives twice the loss, but warmer acid or smaller chips only make it faster. The method needs a dense gas: hydrogen (Mᵣ 2) would barely move a balance that reads to 0.01 g. The clock runs ten times faster than real time.
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