Rp 5: Rates of Reaction

• What is a hypothesis in science?

  A testable proposal explaining an observation
• What reaction is used in the disappearing cross experiment?

  Sodium thiosulfate with hydrochloric acid
• What does the cloudiness in the disappearing cross experiment indicate?

  Formation of solid sulfur in the solution
• What is turbidity in scientific terms?

  Cloudiness of a solution
• How do you start the stopwatch in the disappearing cross experiment?

  After swirling the solution
• Why is reproducibility important in experiments?

  It ensures consistent results across trials
• What issue arises from different people's eyesight in the disappearing cross experiment?

  Variability in seeing the cross clearly
• What is the second method for the required practical?

  Measuring the volume of gas produced
• What gas is produced when magnesium reacts with hydrochloric acid?

  Hydrogen gas
• How is the gas collected in the second method?

  Using an upturned measuring cylinder
• How often do you measure the volume of hydrogen gas?

  Every 10 seconds
• What does a higher concentration of a chemical do to the reaction rate?

  It increases the reaction rate
• Why can the results of both experiments be considered reproducible?

  Both show the same trend with different methods