Today we will continue to look into the 5 factors that will affect the Rate of Reaction in O Level / IB and ICGSE Chemistry.
The rate of chemical reaction depends upon many factors:
1. Temperature
–> Increasing the temperature Increases the rate of a chemical reaction
2. Concentration (when one or more reactants are in solution)
–> Increasing the concentration Increases the rate of a chemical reaction
3. Pressure (when one or more reactants are gases)
–> Increasing the pressure Increases the rate of a chemical reaction
4. Surface Area (when one or more reactants are solid)
–> Increasing the surface area Increases the rate of a chemical reaction
5. Catalysts
–> Adding a Catalysts Increases the rate of chemical reaction
Let’s check out some exam-based questions that test us on these principles:
Question 1:
With which set of conditions will zinc react fastest?
A. Zinc ribbon and dilute acid at 25 degree Celsisus
B. Zinc ribbon and concentrated acid at 45 degree Celsius
C. Powdered zinc and dilute acid at 25 degree Celsius
D. Powdered zinc and concentrated acid at 45 degree Celsius
Question 2:
When sodium thiosulphate reacts with dilute hydrochloric acid, sulphur and sulphur dioxide gas are produced. Which of the following cannot alter the rate of reaction?A. The particle size of sodium thiosulphate.
B. The concentration of hydrochloric acid.
C. The pressure applied to the reaction mixture.
D. The temperature of the reaction mixture.
Question 3:
In terms of particle theory, why do smaller pieces of solid react more quickly with a liquid reactant than an equal mass of larger pieces of solid?
A. There are stronger forces between solid and the colliding particles
B. The smaller pieces of solid have a larger surface area for particles of the liquid to collide with
C. The particles of the liquid collide with each other more frequently
D. The particles of the liquid do not have to break so many bonds in the solid
PS: Remember to try out the above 3 questions and leave down your suggested answers in the “Leave A Reply” section below.
In question no 3 the answer is B.
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sean Reply:
October 19th, 2008 at 5:57 pm
Hi Rija,
You are spot on. Answer is indeed B.
Keep up the good work!
Reply
i dont know rest of the answers so help me out!
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In question 1, the answer is D.
-Higher conc leads to higher freq of effective collisions.
-It has a larger surface area when it is powered so more particles are exposed for reaction
-Lastly, it has a higher temp.Meaning, particles will have more energy for collisions leading to an increase in freq of effective collisions
ps. The increase of effective collisions will result in product particles forming faster as the energy in the particle is greater than the activation energy.
Question 2 the answer is C. Remember that pressure will only affect reactants that are all in the GASEOUS state.Example will be the production of ammonia.
I hope this helps =)
Reply
sean Reply:
October 19th, 2008 at 5:58 pm
Well Done Gary!
Keep it Up and Keep Sharing with others readers!
Cheers
Sean
Reply
1) D
2) C
3) B
Am I correct?
Reply
sean Reply:
October 19th, 2008 at 6:02 pm
Hi Yj,
You are Spot On! Your answers are correct!
Keep up the good work and keep sharing your thoughts with the rest of the readers.
Cheers
Sean
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