KPK 11th Class Chemistry Chapter 9 Chemical Kinetics Short Questions Answers
KPK 11th Class Chemistry Chapter 9 Chemical Kinetics Short Questions with answers are combined for all 11th class(Intermediate/hssc) Level students.Here You can prepare all Chemistry Chapter 9 Chemical Kinetics short question in unique way and also attempt quiz related to this chapter. Just Click on Short Question and below Answer automatically shown. After each question you can give like/dislike to tell other students how its useful for each.
Class/Subject: 11th Class Chemistry
Chapter Name: Chemical Kinetics
Board: All KPK Boards
- Malakand Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
- Mardan Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
- Peshawar Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
- Swat Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
- Dera Ismail Khan Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
- Kohat Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
- Abbottabad Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
- Bannu Board 11th Class Chemistry Chapter 9 Chemical Kinetics short questions Answer
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KPK 11th Class Chemistry Chapter 9 Chemical Kinetics Short Questions Answers
- a) rate = K[NO]2[O2]
- b) rate = K[NO]2
In the above equation the sum of the exponent of the concentration terms is equal to three i.e 2 + 1 = 3. Therefore the equation is third order.
- b) rate = K[NO]2[O2]
In the above equation the sum of the exponent in rate expression is 2. Hence it is second order reaction.
The effective collisions among molecules are must to cause a chemical reaction i.e the molecules with sufficient K.E. The K.E must be enough so the molecules overcome the repulsive forces and cause the atoms in the molecules to vibrate violently. Thus bonds holding atoms together are broken by these violent vibrations, and new bonds are formed. The minimum energy required for the reacting molecules to convert them into products is called activation energy. The activation energy depends upon the nature of the reactants( bond energy) and is therefore, a characteristic value for each, equal to or greater than the energy of activation, reaction occur, if the energy of the colliding molecules is less than the energy of activation, no reaction occurs.
The rate reaction depends upon the following factor.
- The nature of the reactants.
- The conctration of the reactants.
- The particle size of a solid reacting with gases
- The temperature of the reaction mixture
- The pressure or absence of a catalyst.
Reasons No.1 Raising the temperature increases the K.E of the molecules and speed up the molecules motion. This results in more collisions in a given time and chances of the reaction increases.
Reason No.2 The molecules(or atoms) to react must have a minimum energy available to them called activation energy. At high temperature the proportion of reactant molecules with sufficient energy to react (energy greater than activation energy: E> Ea) is significantly higher. In short higher is the temperature, the greater is the chance of the reactants having energy greater than the activation energy of the reaction and higher will be the rate of reaction.
a. The pressure is doubled.
If the pressure is doubled of a gaseous reactants A and B, the volume will decrease. The molecules come close together which result in more frequent colloision among molecules and hence the rate of a chemical reaction increases.
- The number of molecules of gas A is doubled.
When the concentration of a gas A increases the rate of a chemical reaction will also increases because in this case more collisions among molecules will take place and hence the rate of a reaction increases.
- The temperature is decreased at constant value.
A decrease in temperature decreases the rate of a reaction. Lowering the temperature decreases the K.E of the molecules and hence lowers molecular motion. This results in fewer collisions in a given time and chances of the reaction to occur decreases. Secondly, the molecules of gas A and B to react must have a minimum energy available to then called activation energy.
- Given the reaction
CO + NO2 CO2 + NO
The rate equation can be written as
Rate = K[CO][NO2]
The order of reaction = 1 + 1 = 2
Hence the sum of the exponents of the concentration terms is equal to 2. Therefore, the reaction is second order.
- [CO] = 0.025 mol/L
[NO2] is 0.040mol/L.
Rate constant = K = 0.50 liter / mol sec
The rate equation can be written as
Rate = K[CO][NO2]
Putting the values. We get
Rate = 0.50 0.0250.040 = 510-4 mol litre-1 sec1.
All collisions between reactant molecules do not lead to reaction. For a reaction to occur effective collisions among molecules i.e the molecules with sufficient K.E must occur. The K.E must be enough so the molecules overcome the repulsive forces and cause the atom in the molecules to vibrate violently. Thus bonds holding atoms together are broken by these violent vibrations, and new bonds are formed. The minimum energy required for the reacting molecules to convert them into products is called activation energy. The activation energy depends upon the nature of the reactants (bond energy) and therefore, a characteristic value for each, equal to greater than the energy of activation, reaction occurs, if the energy of the colliding molecules is less than the energy of activation, no reaction occurs.
For a reaction to occur not only effective collision are sufficient. Hence the manner in which they collide is also important. Some molecules must be oriented in a very specific manner for a reaction to occur; other molecules may react when colliding in any of a number of random orientations.
