Equipment:
// Sodium thiosulfate solution (of concentrations 0.1M, 0.2M, 0.3M, 0.4M).
// Hydrochloric acid (2M).
// 100cm3 conical flask.
// 10cm3 measuring cylinder.
// Dropping pipette.
// Small piece of plain paper with a large X drawn with think black pen.
// Stopwatch.
// Goggles.
Variables:
Independent - The concentration of sodium thiosulfate solution (0.1M, 0.2M, 0.3M, 0.4M).
Dependent - The time taken for the cross to not be seen.
Control -
// Concentration and volume hydrochloric acid/ volume of sodium thiosulfate solution - to ensure that the rate of reaction is only being altered by the concentration of the sodium thiosulfate solution.
// Temperature of the solution - As temperature is another factor that increases the rate of …show more content…
Put 50 cm3 of sodium thiosulfate solution, with the concentration 0.1M, into the conical flask.
// 2. Measure 5 cm3 of hydrochloric acid in a small measuring cylinder, using a pipette to ensure an accurate amount is measured.
// 3. Pour the hydrochloric acid to the flask and immediately start the clock. Gently swirl the flask to mix the solution and place it on the cross.
// 4. Look down at the cross from above. When the cross can no longer see the cross stop the clock and note the time to the nearest second. Record this in the table.
// 5. As soon as possible, pour the solution down the sink and rinse the flask thoroughly using water, to ensure that there is no solution remaining to interfere with the next results.
// 6. Repeat steps 1-5 twice more with the concentration 0.1M, and three times with each concentration of sodium thiosulfate solution (0.2M, 0.3M, 0.4M)
Risk assessment:
// Hydrochloric acid is an irritant. Wear goggles to prevent it being splashed in eye, and if any gets on your skin, wash with water immediately.
// Sulfur dioxide gas is produced, which can trigger respiratory problems, especially dangerous for asthmatics. Ensure that the room is well ventilated, and if you feel short of breath, leave the room
// Sodium thiosulfate solution (of concentrations 0.1M, 0.2M, 0.3M, 0.4M).
// Hydrochloric acid (2M).
// 100cm3 conical flask.
// 10cm3 measuring cylinder.
// Dropping pipette.
// Small piece of plain paper with a large X drawn with think black pen.
// Stopwatch.
// Goggles.
Variables:
Independent - The concentration of sodium thiosulfate solution (0.1M, 0.2M, 0.3M, 0.4M).
Dependent - The time taken for the cross to not be seen.
Control -
// Concentration and volume hydrochloric acid/ volume of sodium thiosulfate solution - to ensure that the rate of reaction is only being altered by the concentration of the sodium thiosulfate solution.
// Temperature of the solution - As temperature is another factor that increases the rate of …show more content…
Put 50 cm3 of sodium thiosulfate solution, with the concentration 0.1M, into the conical flask.
// 2. Measure 5 cm3 of hydrochloric acid in a small measuring cylinder, using a pipette to ensure an accurate amount is measured.
// 3. Pour the hydrochloric acid to the flask and immediately start the clock. Gently swirl the flask to mix the solution and place it on the cross.
// 4. Look down at the cross from above. When the cross can no longer see the cross stop the clock and note the time to the nearest second. Record this in the table.
// 5. As soon as possible, pour the solution down the sink and rinse the flask thoroughly using water, to ensure that there is no solution remaining to interfere with the next results.
// 6. Repeat steps 1-5 twice more with the concentration 0.1M, and three times with each concentration of sodium thiosulfate solution (0.2M, 0.3M, 0.4M)
Risk assessment:
// Hydrochloric acid is an irritant. Wear goggles to prevent it being splashed in eye, and if any gets on your skin, wash with water immediately.
// Sulfur dioxide gas is produced, which can trigger respiratory problems, especially dangerous for asthmatics. Ensure that the room is well ventilated, and if you feel short of breath, leave the room