* Guiding Question: How does the change in temperature affect the rate of reaction?
* Objectives: The objective of this experiment is to see how temperature affects reaction rates.
* Hypothesis: We think that temperature increases the rate of reaction because the increase in temperature increases the energy of the particles and therefore overcomes faster the activation energy.
1. Independent: Temperature (ï¿½C)
2. Dependents: Time (s) and rate of reaction (s -1)
3. Control: Volume (ml) and concentration (M) of HCl and Na2S2O3.
a) Transfer 50 ml 0.0400 M sodium thiosulfate solution into a 50 ml flask.
b) With a marker make a black cross in a paper and put it below the flask.
c) At room temperature quickly pour 5ml HCl of a 2M solution
d) Measure the time needed for the black cross to disappeared.
e) Repeat this procedure and then place the flask in a hot plate using a thermometer and vary the temperature to 30 ï¿½C, 40 ï¿½C, 50 ï¿½C and 60 ï¿½C.
f) Repeat the experiment twice for each temperature and find the average.
i. 2 measuring cylinder (50 ml)
ii. Thermometer 10 ï¿½C – 110 ï¿½C
iv. 2 flasks (250 mL)
v. 60 ml of a 2M solution of HCl
vi. 600 ml of a 0.04 M solution of Na2S2O3
Sodium Thiosulfate ions (0.04 M) with different temperatures ï¿½C
mL HCL (2M)
Looking at the graph and table, we can see that as the temperature increase, then the rate of reaction increases too. This can be defined and explain by the collision model. Particles can only react when they collide. If the substance is heat, then the particles move faster because they would started to bounce around the space faster because they have receive more energy. So they would bounce around more therefore they are more likely to collide.
Some problems during the experiment were that we just have one hot plate so we loose time waiting for the other team to finish with their results. It was complicated because we couldn’t have enough space to record everything that was happening because there were two groups per table.
A solution to this problem is that for that specific part when we need the hot plates, we can share the data obtained in the whole table members. So we can continued the experiment at a faster rate so we can start doing more researches for the conclusion. And in this way the observations would have been more accuracy for both groups.