Factors Affecting Rate of Reaction
Before, what are the factors that affect the rate
of the reaction?
You must have made sugar water. Why is sugar more soluble in hot water? Temperature is one of the factors that affect the solubility of substances. Temperature is also a factor affecting the rate of reaction. Other factors affecting the reaction rate are surface area, concentration, and catalyst.
You must have made sugar water. Why is sugar more soluble in hot water? Temperature is one of the factors that affect the solubility of substances. Temperature is also a factor affecting the rate of reaction. Other factors affecting the reaction rate are surface area, concentration, and catalyst.
1.
Concentration
Solutions with large concentrations (concentrated) contain finer particles,
when compared with aqueous solutions. The
higher the concentration means the more molecules in each unit of space,
resulting in the collision between molecules more frequent and the reaction
progresses faster. The
higher the concentration of a solution, the greater the rate of reaction.
2.
Touch
surface area
A substance will react when mixed and collide. In
the mixing of reactants consisting of two or more phases, the collision takes
place on the surface of the substance. A
fine powdered solid has a larger surface area of touch surface than a
plate-shaped solid or grain. The
more surface area of the particle, the collision frequency is likely to be
higher so that the reaction can take place more quickly. The
reaction rate is directly proportional to the surface area of the reactant.
3.
Temperature
Every particle is always moving. As
the temperature rises, the motion (kinetic) energy of the particles increases
so that more particles have kinetic energy above the activation energy (Ea). The temperature
rise will increase the reaction rate.
For every temperature rise of 10oC, the reaction rate becomes two to three times faster than before. In general, the formula for calculating the reaction rate at a given temperature is as follows:
For every temperature rise of 10oC, the reaction rate becomes two to three times faster than before. In general, the formula for calculating the reaction rate at a given temperature is as follows:
R2 = (A) R1 T2-T1
t
|
R2 = reaction rate at a
certain temperature
R1 = initial reaction rate
T1 = initial temperature
T2 = temperature at v2
A = multiple rate of reaction
t = time of reaction
R1 = initial reaction rate
T1 = initial temperature
T2 = temperature at v2
A = multiple rate of reaction
t = time of reaction
4.
Catalyst
The catalyst is a substance that can enlarge the rate of reaction, but does not undergo a permanent chemical change, so that at the end of the reaction the substance can be recovered. The catalyst accelerates the reaction by lowering the activation energy (Ea) price. Catalysis is an event of increased reaction rate as a result of the addition of a catalyst. Although the catalyst decreases the activation energy of the reaction, it does not affect the energy difference between the product and the reagents. In other words, the use of a catalyst will not alter the enthalpy of the reaction.
Based on the phase of the catalyst consists of homogeneous catalysts and heterogeneous catalysts.
The homogeneous catalyst is a catalyst having a phase equal to the phases of the reactant.
The catalyst is a substance that can enlarge the rate of reaction, but does not undergo a permanent chemical change, so that at the end of the reaction the substance can be recovered. The catalyst accelerates the reaction by lowering the activation energy (Ea) price. Catalysis is an event of increased reaction rate as a result of the addition of a catalyst. Although the catalyst decreases the activation energy of the reaction, it does not affect the energy difference between the product and the reagents. In other words, the use of a catalyst will not alter the enthalpy of the reaction.
Based on the phase of the catalyst consists of homogeneous catalysts and heterogeneous catalysts.
The homogeneous catalyst is a catalyst having a phase equal to the phases of the reactant.
Example: Fe3 + ion as a
catalyst for ion I- and S2O82-oxidation reactions; NO gas as a
catalyst in reaction in air.
The heterogeneous catalyst is a catalyst having a phase different from that of the reactant agent.
The heterogeneous catalyst is a catalyst having a phase different from that of the reactant agent.
Example: Pt or Ni in solid form can
catalyze the reaction of ethene addition with H2 gas.
https://youtu.be/D_eXilkdFc0
https://youtu.be/D_eXilkdFc0
Can you explain and give example of such heterogeneous and homogeneous phases?
BalasHapusThe heterogeneous is a mixture consisting of two or more substances having different phases. For example, sand is introduced into water, this mixture is a heterogeneous mi because it consists of materials having different phases, the sand in the solid phase and the water in the liquid phase and the homogeneous is a mixture consisting of 2 or more substances in the same phase. For example a small amount of salt (NaCl) is introduced into water, the salt will slowly disappear. The salt that has been inserted is soluble in water and because the salt, water and salt dissolves, it forms a new substance that has different properties from the pure substance. The water in pure time has no taste. But after salt is added, the water will have saltiness as well as salt. Salt at a pure slalu-shaped moment but after being inserted in brine changes liquid.
HapusGive an example of a problem proving that the temperature affects the reaction rate.
BalasHapusFresh fish are sold in supermarkets are always placed in containers that are given ice to be durable and not quickly rotten. Very low temperatures will slow down the process of spoilage of fish or slow down the reaction of decay caused by certain bacteria.
HapusWhy does the catalyst affect the reaction rate? Are examples of chemical reactions that are affected by the catalyst? And what characteristics of a compound are said to be catalysts?
BalasHapusThe catalyst may affect the reaction rate because the catalyst can reduce the energy required for the reaction to occur. Examples of the chemical reactions of Ziegler-Natta catalysts used for the mass production of polyethylene and polypropylene. Characteristics of the catalyst are:
Hapus1. The catalyst does not undergo permanent changes in the reaction, but is involved in the reaction mechanism.
2. The catalyst accelerates the reaction rate but does not change the type or number of reaction products.
3. The catalyst may decrease the activation energy, but does not alter the enthalpy of the reaction.
4. The catalyst alters the reaction mechanism by providing stages having a lower activation energy.
5. The catalyst has a specific action, meaning it can only catalyze a particular reaction.
6. Catalysts are only needed in small quantities.
7. The catalyst can be poisoned.
Is it some formula to know what factor affacting
BalasHapusThere at the temperature there is a formula
HapusR2 = (A) R1 T2-T1/t
R2 = reaction rate at a certain temperature
R1 = initial reaction rate
T1 = initial temperature
T2 = temperature at v2
A = multiple rate of reaction
t = time of reaction