Laporan Percobaan Faktor yang Mempengaruhi Laju Reaksi (Factors Affecting the Rate Reaction)

  PURPOSE:

1. Knowing concentration  influence on reaction rate
2. Knowing the influence of surface area on reaction rate
3. Knowing the influence of temperature on reaction rate
4. Knowing the influence of catalyst on reaction rate

BASIC THEORY

• EFFECT OF SOLUTION CONCENTRATION ON REACTION RATE

The greater the concentration of reagent that reacted the greater the rate of reaction. This is because with the greater concentration of reagent, the more the amount of reagent that exist, so the likelihood of collisions inter particlel will be even greater. If the possibility of collisions inter reagenti  greater, might have formed the greater the reaction.
We take the example of reaction formation of gas reactants solid and liquid, such as the following:
2Fe (s) 6HCl (aq) " 3 FeCl3 (aq) 3H2 (g)
If the volume of hydrogen gas that is formed is measured, the influence of concentration on reaction rate can be described as in the above graph
From the chart above can be seen that a greater concentration of reactants will form a product faster than the reactant concentration mempuyai smaller. So, semain large concentration of a reactant, the faster the reaction rate.

• EFFECT OF SURFACE AREA ON REACTION RATE

The rate of reactions that occur in heterogeneous reaction systems depend on surface area in contact between the phase reactants. The reaction between solids and liquids or solids and gases will be faster if the surface area of solids multiplied touch.
If  the surface area the greater the rate of reactant agent aka the greater reaction. This happens because when a large surface area semain would then likely intersect between the reagent would be even greater as well. For  example, for the same magnitude as we iron reacting with HCl solution. Iron that exist in a state of powder will react faster than existing in a state bar, because there is the same weight, surface area of powder will be greater than the surface area of the stem.

•  EFFECT OF TEMPERATURE ON REACTION RATE

Generally the higher the temperature will accelerate the reaction. This is because with increasing temperature, the kinetic energy of reactant particles bigger. As a result, movement between molecules will be more random, so the possibility of intermolecular collisions will be even greater.

• EFFECT OF CATALYST ON REACTION RATE

Catalysts are substances that can mempercepar reaction rate, but no change is eternal or permanent chemicals so that at the end of the reaction of these substances can be recovered.
The presence of catalyst will cause the formation of additional reaction stages, namely the binding stage of the catalyst and catalyst in the final stages of the release reaction. This catalyst is specific, meaning that only works for a particular reaction.

EQUIPMENT AND MATERIALS:

1.  1 M HCl solution
2.  2 M HCl solution
3.  Magnesium Ribbon
4.  Test tube
5.  Na₂S₂O₄ solution of 0.2 M
6.  Cu Plate
7.  Zn metal powders
8.  Beaker
9.  Stop Watch
10 . Burning Spiritus
11.  Matches
12. Three feet
13. Kassa

WORK STEP

1)  Determine the effect of concentration on reaction rate

• Input 1 M HCl solution into a test tube by 5 mL
• Add the magnesium ribbon into it and observe the change and record the time it takes to run out of magnesium ribbon reacts
• Perform the same experiment with 2 M HCl solution

2) Determine the influence of surface area on reaction rate

• Input 1 M HCl solution into a test tube by 5 mL
• Add the magnesium ribbon measuring 2 cm without cut into it and observe the change and record the time it takes to run out of magnesium ribbon reacts
• Perform the same experiment with magnesium ribbon 2 cm which had been cut into pieces

3) To observe the effect of temperature on reaction rate

• Make a cross on a piece of paper
• Enter Na2S2O4 50 mL 0.2 M solution into a beaker. Put the beaker on paper yag crossed. Measure and record temperatures. Add 5 mL of HCl 2 M. Measure and record the time required since the addition of HCl solution until a cross is not visible anymore.
• Input 50 Ml Na2S2O4 0.2 M solution into another beaker. Heat until the temperature rises above room temperature 100C (100C above the temperature in step b). Put the beaker on paper yag had crossed, then add 5 Ml 2 M HCl solution and record the time as above.

4) Determine the effect of catalyst on reaction rate

• Two tubes are prepared and marked on each test tube with the letters A and B.
• One fruit plate copper metal which has a length of 1 cm sanded
• Zn metal powders incorporated into the test tube A and 5 mL of HCl 2 M was inserted into the tube
• d. Metal powders of Zn and Cu are sanded metal plate inserted into the test tube B
• A total of 5 ml HCl 2 M is inserted into the test tube B containing Zn and Cu metal plate
• Observe what happens to the tubes A and B

RESULT

1.    Knowing the influence of concentration on reaction rate

CONCENTRATION	TIME
HCl  2 M	88 sekond
HCl  1 M	158 sekond

2.    Knowing the influence of surface area on reaction rate

SHAPE	TIME
2 cm without chopped	168 sekond
2 cm chopped	163 sekond

3.    Knowing the influence of temperature on reaction rate

BEAKER GLASS	TEMPERATURE	TIME
I	300	15 sekond
II (heated)	400	14 sekond

4.    Knowing the influence of catalyst on reaction rate
a. Can you explain the differences in chemical reactions that occur in tube A and B?
b. Why copper metal plates need to be sanded before use?
c. Is copper metal plate in this experiment serves as a catalyst?
Answer:

No	differences	A	B
1.	Zn granules	Be black color	were no change
2.	sedimentation	_	+
3.	Reaction	slow	fast

a.     

b.    Yes, in this experiment, Cu serves as a catalyst. Because in this experiment to accelerate the reaction of copper metal.

 DATA ANALYSIS

• How does the influence of concentration, temperature, surface area and catalyst on reaction rate?

Answer :

Concentration, temperature, surface area and catalytic effect on reaction rate. High concentration of substances that accelerate the rate of reaction. Evident from the results of experiments which showed that the HCl concentration was higher time to react more quickly. Higher temperatures indicated a molecular collisions more quickly and frequently, thus speeding up the reaction. evident from the results of experiments showing that HCl 100 more high-temperature has a shorter reaction time.
Magnesium ribbon is cut in pieces to expand the area that reacts, so the reaction will go faster.
Substance in the reaction involving the catalyst, making the reaction go faster.

CONCLUSION

1. The HIGHER concentration of a substance the faster rate of reaction 
2. If the surface area REAGENT greater substance, then the reaction rate will be greater the 
3. The higher temperatures will accelerate the reaction 
4. A catalytic reaction make faster reaction 
5. In accelerating the rate of reaction, the catalyst has not changed so that at the end of the reaction of the catalyst material can be recovered

REFERENCE

1)    Sudiono sri, dkk.2005.Kimia Untuk Kelas XI. Klaten : Intan pariwara

2)    Justiana Sandri, Muchtaridi.2009.Chemistry For Senior High School.