practical - reaction rate experiments

Describe the magnesium metal and hydrochloric acid experiment

-use a measuring cylinder to measure 50 cm³ of hydrochloric acid into a conical flask.

– Attach Chronicle flask to a bong and delivery tube. Place delivery tube into container filled with water.

– Then place up turned measuring cylinder filled with water over delivery tube.

– Add 3 cm strip of magnesium to acid and start the stopwatch.

– The reaction produces hydrogen gas which is trapped in a measuring cylinder every 10 seconds measure the volume of hydrogen gas in the measuring cylinder.

-continue until no more hydrogen has been given off.

– Repeat the experiment using different concentrations of hydrochloric acid

What is the problem with the disappearing cross practical

The problem with the experiment is that people have different eyesight so some people see the cross for longer than others so the results may not be the same.

– A solution to this is using the same size printed crosses to reduce

Describe the disappearing cross practical

– use a measuring cleaner to put 10 cm³ of sodium thiosulfate solution into the Chronicle flask.

– Place a Chronicle flask onto a printed black cross.

– Add 10 cm³ or hydrochloric acid into the Chronicle flask.

– swirl solution and start the stopwatch.

– Look down at the top of the flask, after a certain amount of time the solution will turn cloudy.

– Stop the clock when you no longer see the X

– Carry out the experiment again using a lower concentration of sodium thiosulfate solution.

– Repeat the whole experiment and calculate mean values for each concentration of sodium thiosulfate sulphate solution

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