Measuring RoR

    Cards (4)

    • How can you measure RoR when gas is given off? (collecting gas)
      • Measure time and collect gas in an upside down measuring cylinder in a trough of water or in a gas
      • Measure time and change in mass
    • How can you measure RoR when a precipitate is formed?
      • Put a black cross below a beaker containing one reactant
      • Time how long it takes for the cross to disappear after the second reactant is added
    • Why is the precipitation method not very accurate?
      • Its subjective so people are most likely to disagree over the exact point at which the cross is no longer visible
    • How can you measure the RoR using a digital balance (change in mass)
      • When gas is produced this will cause the mass to decrease
      • This can be carried out on a digital balance and the RoR can be calculated by recording the mass at regular time intervals