Thursday, October 13, 2011

Rates of Reaction Experiment

If you order your cheap custom essaysessay from our custom writing service you will receive a perfectly written assignment on Rates of Reaction Experiment. What we need from you is to provide us with your detailed paper instructions for our experienced writers to follow all of your specific writing requirements. Specify your order details, state the exact number of pages required and our custom writing professionals will deliver the best quality Rates of Reaction Experiment paper right on time.

Out staff of freelance writers includes over 120 experts proficient in Rates of Reaction Experiment, therefore you can rest assured that your assignment will be handled by only top rated specialists. Order your Rates of Reaction Experiment paper at affordable prices with!

Rates of Reaction Experiment � Design Type


In this experiment, Sodium Thiosulfate is reacted with Hydrochloric acid to study the affect of changing the concentration of one of the reactants, on the reaction rate. The products formed are Sodium Chloride, Water, Sulfur Dioxide and Sulfur.

NaSO(aq) + HCl(aq) = NaCl(aq) + HO + SO(aq) + S(s)

Buy custom Rates of Reaction Experiment term paper

As the precipitate of sulfur forms, it masks the cross-drawn on the filter paper and a time for the reaction to complete can be measured.


As the concentration of one of the reactants in a reaction increases, reaction rate also increases.


To show the effect of concentration on rate of reaction.


M HCl(aq) x Burette Stand and clamp

0.5 M NaSO(aq) 10 mL measuring cylinder

Stop Watch x Burette

Sheet Of White Paper with a Cross (pencil) Conical Flask


1. Placed 50mL of thiosulfate solution in the 50mL conical flask using the burette. Added 5mL of dilute HCl(aq) to the solution in the flask using the 10mL measuring cylinder, and at the same time started the stopwatch. Swirled the flask twice and placed it over the piece of paper with the mark on it.

. Looked vertically over the conical flask and timed the reaction by stopping the stopwatch when the cross was no longer visible.

. Rinsed the flask.

4. Repeated the experiment using 40, 0, 0 and 10mL of the thiosulfate solution made up each time to a volume of 50mL with distilled water, and still used 5mL of HCl(aq).


NB. A lab coat, safety glasses and gloves were worn during the experiment.


Note Concentration of NaSO(aq) calculated before (50mL) adding to HCl (55mL).

Dilution of NaSO(aq)

Attempt 1 4 5

HO (mL) 0 10 0 0 40

NaSO(aq) (mL) 50 40 0 0 10

Concentration of NaSO(aq) (mol/L) 0.5 0. 0.15 0.1 0.05

Attempt 1 4 5

Concentration of NaSO(aq) (mol/L) 0.5 0.0 0.15 0.10 0.05

Concentration of HCl(aq) (mol/L) .00 .00 .00 .00 .00

Agitation (Swirls)

Time (s) 7.87 0.8 7. 5. 14.50

1/Time 0.0588 0.00 0.0687 0.01687 0.00745

The slope of the Concentration Vs. Time graph at two different points



m1=-48 (sf)



m=-1.5 x 10 (sf)

The slope is steeper where the concentration of the thiosulfate solution is lower, as there are less particles in the solution for the HCl(aq) to react with to form S(s) therefore the solution requires a longer amount of time to react. The slope is shallower where the concentration is higher as there are more particles in the solution to react with HCl(aq) to form S(s) and therefore there is a higher chance of effective and frequent collisions between reactants, hence more products are formed and therefore the reaction time is shorter.

Analysis and Evaluation

The independent variable in this experiment was the Concentration of NaSO(aq).

The dependent variable in this experiment was time i.e. reaction rate.

The controlled variables in the experiment were atmospheric pressure, temperature, concentration of HCl(aq), the amount of agitation and the state of subdivision of the reactants.

The graph of Concentration of NaSO(aq) Vs. Time clearly indicates that as concentration is decreased, time for the reaction to occur increased.

The graph of the Reaction rate clearly indicates that as concentration increased, reaction rate also increased. Therefore from this experiment it is evident that reaction rate is directly proportional to the concentration of the reactants.

Random Errors

• If there are variations in eye level when taking the burette reading then the amount of thiosulfate solution will increase or decrease, and as a result the reaction rate will also increase or decrease.

• If there are variations in the ambient temperature or atmospheric pressure, then the amount of thiosulfate solution or hydrochloric acid will increase or decrease, and as a result the reaction rate will also increase or decrease.

Systematic Errors

• If the burettes and the measuring cylinder have been incorrectly calibrated by the manufacturer, then the amount of NaSO(aq) or HCl(aq) in the conical flask would have been higher or lower than required, thus the concentration of these two substances in the conical flask may have been affected, and consequently increased or decreased time.

• If a contaminated sample was used in the experiment, then the concentrations would have been affected, thus lengthening or shortening the times to react.

• The exact point where the cross disappears from sight is hard to gauge, therefore the time taken for the cross to disappear may not have been consistent.

• The amount of agitation may have varied with each attempt in the experiment.

Some improvements that could have been made to the design of the experiment to reduce errors are

• To do the experiment in a temperature controlled environment where the atmospheric temperature and pressure can be monitored for small increases or decreases and can then be rectified.

• Use a machine to agitate the solution to keep the agitation consistent.

• Repeat the experiment.


The Rate of reaction is directly proportional to the concentration of the reactants. As the concentration of NaSO(aq) increases, reaction rate increases.

Please note that this sample paper on Rates of Reaction Experiment is for your review only. In order to eliminate any of the plagiarism issues, it is highly recommended that you do not use it for you own writing purposes. In case you experience difficulties with writing a well structured and accurately composed paper on Rates of Reaction Experiment, we are here to assist you. Your persuasive essay on Rates of Reaction Experiment will be written from scratch, so you do not have to worry about its originality.

Order your authentic assignment from and you will be amazed at how easy it is to complete a quality custom paper within the shortest time possible!

No comments:

Post a Comment