Collision Theory Of Chemical Reactions

Step 1: Concept
First order rate constant .
Step 2: Analysis
.
Rate .
Step 3: Conclusion
Rate .
Final Answer: (D)

Step 1: Concept
First order rate constant .
Step 2: Analysis
.
Rate .
Step 3: Conclusion
Rate .
Final Answer: (D)

Step 1: Concept
Amino acids exist as Zwitterions at their isoelectric point, but change form in acidic or basic media.
Step 2: Analysis
At (acidic medium), the carboxylate group ( ) of the Zwitterion accepts a proton.
Step 3: Conclusion
The structure becomes a cation: .
Final Answer: (B)

Step 1: Wave Propagation
Thermal radiation is an electromagnetic wave and follows the same rules as light.
Step 2: Medium Change
When a wave enters a new medium, its speed and wavelength change based on the refractive index.
Step 3: Invariant Property
The frequency of a wave is determined by the source and remains constant regardless of the medium.
Final Answer: (b)

Step 1: Kepler's Second Law
According to the Law of Conservation of Angular Momentum, is constant.
Step 2: Speed-Distance Relationship
Speed ( ) is inversely proportional to the distance ( ) from the Sun.
Step 3: Analysis
Distance is minimum at point A (Perihelion), so the linear speed is maximum at that point.
Final Answer: (c)

Step 1: Concept
Einstein's photoelectric equation: .
Step 2: Analysis
Energy of photon .
.
Step 3: Conclusion
.
Final Answer: (A)

Concept: Reaction rate depends on concentration, temperature, and nature of reactants.

Step 1: Temperature affects kinetic energy → affects rate.

Step 2: Number of particles per mL = concentration → affects rate.

Step 3: Bond stability affects activation energy → affects rate.

Step 4: Pressure mainly affects gaseous systems, not liquids.
Conclusion:
Pressure does not influence liquid-phase reaction rate.

Concept: Rate is proportional to stoichiometric coefficients:

Step 1: From reaction: 5Br → 3Br .

Step 2: Relation:

Step 3: Substitute given rate:

Step 4: Calculate: Conclusion:
Rate = 0.042 M s

Concept: Arrhenius equation:

Step 1: Rate .


Step 2: Temperatures:

Step 3: Substitute in Arrhenius equation:

Step 4: Activation energy: Conclusion:
Activation energy = 78.3 kJ mol

Concept:

Step 1: Find order .


Step 2: New concentration.

Concept: Arrhenius equation:

Step 1: Given condition.


Step 2: Substitute.


Step 3: Conclusion.
Rate constant becomes independent of temperature.

Concept:

Step 1: Effect of volume change.

Step 2: Apply rate law.

Step 3: Compare with original rate.

Concept: For a reaction , the rate can be expressed as:

Step 1: Identify stoichiometric coefficients.
Here, coefficient of is 1, coefficient of is 2.

Step 2: Apply rate relation.
Rate of disappearance of : Rate of formation of :

Step 3: Final value.