• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5

# What factors affect the rate at which hydrochloric acid reacts with sodium thiosulphate?

Extracts from this document...

Introduction

What factors affect the rate at which hydrochloric acid reacts with sodium thiosulphate? Planning: This investigation is about rates of reaction and what affects them. In this case I am going to look at hydrochloric acid and sodium thiosulphate which is a precipitation reaction. They react as in the equations below: Sodium thiosulphate + hydrochloric acid -> sodium chloride + sulphur + sulphur dioxide + water Na2S2O3(aq) + 2HCl (aq) -> 2NaCl (aq) + S(s) + SO2(g) + H2O(l) For a reaction to occur the reactants must a) collide b) Collide with sufficient energy in order to make a successful collision. The collision theory is useful when carrying out this experiment because it explains why rates of reactions differ. The concentration of a solution effects the rate of reaction because the rate depends on how frequently the molecules of the reacting substances collide. A more concentrated substance has more molecules in a given volume than a more dilute substance. Therefore the frequency of successful collisions is greater, and the reactions will occur more quickly. The 4 factors that control the rate of a reaction are: Temperature, concentration, surface area and the use of a catalyst. Variables: Temperature- I will conduct my experiments at room temperature as an increase could speed up the reaction. This is my controlled variable. Concentration- I will be altering the concentration of Sodium thiosulphate and this will be my independent variable. ...read more.

Middle

The measures of Hydrochloric acid will all be the same (5cm) and measured with droppers at eye level to get the most accurate readings possible. I will also use the same method for mixing all the solutions, rinsing all the conical flasks out after each experiment in case some of the liquid is left, making the volumes irregular. I will also make sure that I add both the water and the sodium thiosulphate at exactly the same time (into the conical flask with the hydrochloric acid in it), or it could affect the results of the experiment. I am going to start the stopwatch at the exact time as I put the water and the sodium thiosulphate into the conical flask. To do this it is a lot easier if there are two people doing the experiment, so one person can put the two substances in, and one person can start the stopwatch. Measurements I am going to take a range of readings, ranging from 50cm of sodium thiosulphate (and 0ml of water) to 10cm of sodium thiosulphate (and 40ml of water.) In my preliminary experiment I stopped taking readings as 5cm of sodium thiosulphate but I found that the reaction took over 10 minutes and that it would be more sensible to stop at 10cm of sodium thiosulphate. I will also take 2 readings for each concentration to make sure my results are more reliable. ...read more.

Conclusion

Before conducting my final experiment I did some preliminary work in order to familiarize myself with the project. This helped to improve the accuracy of my results because I was then able to make any changes in the way I conducted the experiment. My results do seem, on the whole, to fit my conclusion and despite the anomaly I was able to produce a smooth line of best fit. I think that I have obtained sufficient evidence in which to support my conclusion, although taking more than 2 readings would have helped to increase their reliability. For example from 16g/dm- 32g/dm the rate almost doubled by 2.2, which shows that although they do tend to imply that as the concentration doubles, the rate also doubles, it would have been more informative to take the average of 5-6 readings and see if the results changed. If I were to extend this investigation and carry out any further work I could look into the affects of catalysts (and other variables) on reaction times. I could also carry out the same experiment using different substances or by varying the amount of acid instead. It would also be interesting to substitute the 'piece of paper with a black cross on it' for a light sensitive detector which would go out when the reaction had completely clouded over. Therefore my times would be more accurate and my graphs would be more precise. Overall I think my experiments were successful and I believe my evidence was sufficient enough in which to support my hypothesis. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related GCSE Patterns of Behaviour essays

1. ## Sodium thiosulphate reacts with hydrochloric acid to produce a yellow precipitate of sulphur.

It is important to keep the amount of hydrochloric acid because it may alter the rate of the reaction. It is important to keep the temperature the same because the more heat a reaction gets the more kinetic energy it will have so the reaction rate will increase.

2. ## How does the concentration of sodium thiosulphate solution affect the rate of its reaction ...

(0.1), * Hydrochloric acid (1 M), * Distilled water, * 10cm3 measuring cylinder, * 50cm3 measuring cylinder, * 100cm3 conical flask, * Stopwatch, * Thermometer, * Piece of paper with a cross on it, * Safety goggles, * Access to a fume cupboard.

1. ## Investigating the factors influencing the rate of reaction between Sodium Thiosulphate and Dilute Hydrochloric ...

The reaction is used to investigate the relationship between concentration and rate of reaction. When dilute Hydrochloric acid is added to Sodium Thiosulphate solution, a pale, cloudy yellow precipitate of sulphur is formed. This means I will be using the turbidity of the combined chemicals as a measure of how much they have reacted.

2. ## Find out how the rate of hydrolysis of an organic halogen compound depends on ...

CH2 ? CH2 ? CH2 ? OH + I- Ag+(aq) + I-(aq) AgI(s) During the second experiment, the rate of reaction was measured via a conductivity experiment. The equations for the reactions that occurred are: 2-bromo-2-methylpropane - CH3 CH3 ? ? CH3 ? C ? Br + OH- CH3 ?

1. ## Investigation of the rate of reaction of sodium thiosulphate with dilute hydrochloric acid.

3 10 10.59 10.85 11.06 10.83 6 0.6 4 10 11.38 13.26 11.37 12.01 5 0.5 5 10 14.28 15.56 14 14.61 4 0.4 6 10 16.5 17.87 17.43 17.26 3 0.3 7 10 27.19 24.02 23.34 23.68 2 0.2 8 10 37.53 34.59 35.82 35.2 1 0.1 9 10

2. ## How does the Temperature affect the Rate of Reaction between Sodium Thiosulphate and Acid?

As the soon as the cross had disappeared the time was recorded. 7) This was repeated for the other concentrations. The results for the trial experiments are represented below. Experiment at room temperature (20oC): Experiment Volume of stock thiosulphate (cm3) Volume of water (cm3) Concentration of thiosulphate (g dm-3)

1. ## An investigation of factors which might affect the rate of the reaction between sodium ...

will measure the 1/T will measure the rate of the reaction Results When I collect the results I will have to arrange them into a table. The table will consist of five columns. I have designed a blank table shown below: Temp oC First time sec Second time oC Average

2. ## Investigation of factors which might affect the rate of the reaction between sodium thiosulphate ...

stopwatch and time the reaction until the 'X' is obscured from view. When I can no longer see the 'X' then I will stop the clock and record my results. I feel this is a fairly accurate way of recording my results although it does rely on the accuracy of

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to