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The disappearing cross

How does concentration change the time for sulfur to hide the X?

Topic: Reaction ratesGrade: 10Free

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What you do

  1. Add 5 mL of hydrochloric acid to beaker 1. Tip: set the speed to ×5.
  2. Add 5 mL of hydrochloric acid to beaker 2 (half the thiosulfate concentration).
  3. Wait until the X disappears in both beakers and compare the times.

Safety in a real lab

⚠ Sulfur dioxide is released: work in a well-ventilated room.

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