Two rates experiment

Question 1

What is the rate of reaction experiment for Mg and HCl to produce Hydrogen gas?

Answer 1

1. Add a set volume of dilute hydrochloric acid to a conical flask and place on a mass balance
2. Add some magnesium ribbon to the acid and quickly plug the flask with cotton wool
3. start the stopwatch and record the mass on the balance. take readings of the mass at regulat intervals
4. plot the results in a table and work out the mass lost each reading.
5. plot a graph with time on the x axis and mass lost in the y
6. repeat with more concentrated acid solutions but keep the same volume of acid to make it a fair test

Question 2

Sodium thiosulphate and HCl produce a cloudy precipitate

Answer 2

1. The two chemicals are both clear solutions.They react together to form a yellow precipitate of sulphur
2. Start by adding a set volume of dilute sodium thiosulphate to a conical flask
3. place the flask on a piece of paper with a black cross drawn on it add some dilute HCl to the flask and start the stopwatch
4. Now watchg the black cross dissappear through the cloudy sulphur and time how long it takes to go
5. The reaction can be repeated with solutions of either reactant at different concentrations
6. the higher the concentration show the effect of increasing the concentration of HCl on the rate of reaction when added to n excess of sodium thisulphate