Home
Class 12
CHEMISTRY
The activation energy for a first order ...

The activation energy for a first order reaction is 60 kJ `mol^(-1)` in the absence of a catalyst and 50 kJ `mol^(-1)` in the presence of a catalyst. How many times will the rate of reaction grow in the presence of the catalyst if the reaction proceeds at `27^@ `C ?

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to determine how many times the rate of a first-order reaction increases in the presence of a catalyst, given the activation energies in both cases. ### Step-by-Step Solution: 1. **Identify Given Values:** - Activation energy without catalyst (EA1) = 60 kJ/mol - Activation energy with catalyst (EA2) = 50 kJ/mol - Temperature (T) = 27°C = 300 K (since T(K) = T(°C) + 273) 2. **Convert Activation Energies to Joules:** - EA1 = 60 kJ/mol = 60,000 J/mol - EA2 = 50 kJ/mol = 50,000 J/mol 3. **Use the Arrhenius Equation:** The ratio of the rate constants \( k_2 \) (with catalyst) and \( k_1 \) (without catalyst) can be expressed using the Arrhenius equation: \[ \frac{k_2}{k_1} = e^{\frac{-(EA2 - EA1)}{RT}} \] where \( R \) is the universal gas constant (8.314 J/(mol·K)). 4. **Calculate the Difference in Activation Energies:** \[ EA1 - EA2 = 60,000 J/mol - 50,000 J/mol = 10,000 J/mol \] 5. **Substitute Values into the Equation:** \[ \frac{k_2}{k_1} = e^{\frac{-10,000}{(8.314)(300)}} \] 6. **Calculate the Exponent:** \[ \frac{-10,000}{(8.314)(300)} \approx -4.007 \] 7. **Calculate \( \frac{k_2}{k_1} \):** \[ \frac{k_2}{k_1} = e^{-4.007} \approx 0.0183 \] 8. **Find the Rate Increase:** Since \( \frac{k_2}{k_1} \) gives us the ratio of the rate constants, we can find how many times the rate increases: \[ \text{Rate increase} = \frac{1}{0.0183} \approx 54.64 \] ### Final Answer: The rate of reaction will increase approximately 55 times in the presence of the catalyst. ---

To solve the problem, we need to determine how many times the rate of a first-order reaction increases in the presence of a catalyst, given the activation energies in both cases. ### Step-by-Step Solution: 1. **Identify Given Values:** - Activation energy without catalyst (EA1) = 60 kJ/mol - Activation energy with catalyst (EA2) = 50 kJ/mol - Temperature (T) = 27°C = 300 K (since T(K) = T(°C) + 273) ...
Promotional Banner

Topper's Solved these Questions

  • CHEMICAL KINETICS

    ICSE|Exercise INTEXT QUESRTIONS|81 Videos
  • CHEMICAL KINETICS

    ICSE|Exercise EXERCISE (PART- I (OBJECTIVE QUESRTIONS)A.FILL IN THE BLANKS) |54 Videos
  • CHEMICAL KINETICS

    ICSE|Exercise ISC EXAMINATION QUESTIONS (NUMERICAL PROBLEMS )|57 Videos
  • BIOMOLECULES

    ICSE|Exercise ISC EXAMINATION QUSTIONS (PART-I)(DESCRIPTIVE QUESTIONS)|21 Videos
  • CHEMISTRY IN EVERYDAY LIFE

    ICSE|Exercise EXERCISE (PART - II (DESCRIPTIVE QUESTIONS) (LONG ANSWER QUESTIONS))|19 Videos

Similar Questions

Explore conceptually related problems

The activation energy of a reaction is 75.2 kJ mol^(-1) in the absence of a catalyst and 50.14 kJ mol^(-1) with a catalyst. How many times will the rate of reaction grow in the presence of the catalyst if the reaction proceeds at 25^@ C? [R = 8.314 JK^(-1) mole ""^(1) ]

The activation energy of a first order reaction at 300 K is 60 kJ mol^(-1) . In the presence of a catalyst, the activation energy gets lowered to 50kJ mol^(-1) at 300 K . How many times the reaction rate change in the presence of a catalyst at the same temperature ?

Tischenko reaction yields ester in the presence of catalyst which is :

How do temperature and the presence of a catalyst bring about an increase in the rate of a reaction ?

The activation energy for the forward reaction X rarr Y is 60 kJ mol^(-1) and Delta H is -20 kJ mol^(-1) . The activation energy for the reverse reaction is

In the presence of a catalyst, the rate of a reaction grows to the extent of 10^(5) times at 298 K . Hence, the catalyst must have lowered E_(a) by

Why equilibrium constant of a reaction does not change in the presence of a catalyst ?

Assertion: A catalyst increases the rate of a reaction. Reason: In presence of a catalyst, the activation energy of the reaction decreases.

ICSE-CHEMICAL KINETICS-PROBLEM
  1. If a first order reaction has activation energy of 25000 cal and a fre...

    Text Solution

    |

  2. If a first order reaction has activation energy of 25000 cal and a fre...

    Text Solution

    |

  3. The activation energy for a first order reaction is 60 kJ mol^(-1) in...

    Text Solution

    |

  4. For a reaction, the energy of activation is zero. What is the value of...

    Text Solution

    |

  5. The rate constant for the decomposition of hydrocarbons is 2.418 × 10^...

    Text Solution

    |

  6. The decomposition of a hydrocarbon follows the equationk = (4.5 xx 10 ...

    Text Solution

    |

  7. The rate of a reaction triples when temperature changes from 50^@ C to...

    Text Solution

    |

  8. A certain reaction is 50% complete in 20 minutes at 300 K and the same...

    Text Solution

    |

  9. The rate of a reaction increases four times when the temperature chang...

    Text Solution

    |

  10. From the data given below, calculate the average rate of the reaction ...

    Text Solution

    |

  11. When 50 mL of 2M solution of N2 O5 was heated, 0.28 L of O2 at NTP was...

    Text Solution

    |

  12. Consider the following reaction which proceeds in a closed vessel. ...

    Text Solution

    |

  13. Express the rate of following reactions PCl5 to PCl3 +Cl2

    Text Solution

    |

  14. Express the rate of following reactions 2NO2 to 2NO +O2

    Text Solution

    |

  15. Express the rate of following reactions. H2 +I2 hArr 2HI

    Text Solution

    |

  16. Express the rate of following reactions. N2 +3H2 hArr 2NH3

    Text Solution

    |

  17. Identify the reaction order from each of the following rate constants ...

    Text Solution

    |

  18. Nitrogen dioxide (NO2) reacts with fluorine (F2) to yield nitryl fluor...

    Text Solution

    |

  19. Nitrogen dioxide (NO2) reacts with fluorine (F2) to yield nitryl fluor...

    Text Solution

    |

  20. Nitrogen dioxide (NO2) reacts with fluorine (F2) to yield nitryl fluor...

    Text Solution

    |