Rate experiments involving precipitation

Reaction between Sodium Thiosulfate and Hydrochloric Acid

When sodium thiosulfate reacts with hydrochloric acid (HCl), a yellow solid called sulfur forms. This makes the solution go cloudy. We can use this cloudiness to measure how fast the reaction happens by timing how long it takes for the solid to form.

Variables to Keep the Same

• Temperature: You can repeat the experiment at different temperatures to see how it affects the reaction speed.
• Volume: Make sure you always use the same amounts of sodium thiosulfate and hydrochloric acid.
• Concentration: The concentration of both solutions must stay the same throughout the experiment.

How Temperature Affects the Reaction

• Higher Temperature: The higher the temperature, the faster the particles move. This makes them collide more often, so the reaction happens quicker.
• Shorter Time = Faster Reaction: If the black mark disappears quicker, the reaction is happening faster!