Question

при 100 С некоторая реакция заканчивается за 10 мин. Принимая температурный коэффициент скорости реакции равным 3, расчитайте, через какое время закончится эта реакция, еслипроводить ее при 60 С; при150 С. (ответ: 810 мин; 2,47 с) нужно решение, заранее спасибо

Answer 1

Если р-я проходит одна и таже, то концентрации веществ постоянны и Vр-и зависит только от температурного коэффициента гамма(ну пусть будет буква j) в степени (t2-t1)/10, где t1=100, а t2=60;150, V2/V1=j^((t2-t1)/10)

1) t2=60, (t2-t1)/10=(60-100)/10=-40/10=-4, V2/V1=j^(-4)=3^(-4)=1/81=> V2=V1/81, в 81 раз проходит медленее=>время протекания в 81 раз больше=10*81=810мин

2) t2=150, (t2-t1)/10=(150-100)/10=50/10=5, V2/V1=j^5=243=> V2=243V1, в 243 раза р-я проходит быстрее=> время её протекания меньше в 243 раза=10*60/243=2,47сек.

Answer 2

Calculation of Reaction Time at Different Temperatures

To calculate the time it takes for a reaction to complete at different temperatures, we can use the temperature coefficient of reaction rate. The temperature coefficient is a measure of how the rate of a reaction changes with temperature.

Given: - The reaction takes 10 minutes to complete at 100°C. - The temperature coefficient of reaction rate is 3.

We need to calculate the time it takes for the reaction to complete at 60°C and 150°C.

To solve this problem, we can use the Arrhenius equation, which relates the rate constant of a reaction to temperature:

k = A * e^(-Ea/RT)

Where: - k is the rate constant - A is the pre-exponential factor - Ea is the activation energy - R is the gas constant - T is the temperature in Kelvin

We can assume that the activation energy and the pre-exponential factor remain constant for this reaction.

Let's calculate the time it takes for the reaction to complete at 60°C and 150°C.

Calculation at 60°C (333.15 K)

To calculate the time it takes for the reaction to complete at 60°C, we need to find the rate constant at this temperature using the temperature coefficient.

Given: - The reaction takes 10 minutes to complete at 100°C. - The temperature coefficient of reaction rate is 3.

We can use the Arrhenius equation to find the rate constant at 100°C:

k1 = A * e^(-Ea/RT1)

Where: - k1 is the rate constant at 100°C - T1 is the temperature in Kelvin (100°C = 373.15 K)

We can rearrange the equation to solve for the pre-exponential factor A:

A = k1 / e^(-Ea/RT1)

Now, we can use the temperature coefficient to find the rate constant at 60°C:

k2 = k1 * (3^(T2 - T1))

Where: - k2 is the rate constant at 60°C - T2 is the temperature in Kelvin (60°C = 333.15 K)

Finally, we can calculate the time it takes for the reaction to complete at 60°C using the rate constant:

Time2 = 10 minutes * (k1 / k2)

Let's calculate the values:

1. Calculate the pre-exponential factor A: - We need the rate constant at 100°C (k1). - We need the temperature in Kelvin (T1 = 373.15 K). - We need the activation energy (Ea) and the rate constant at 100°C (k1) to calculate A using the Arrhenius equation.

2. Calculate the rate constant at 60°C (k2): - We need the rate constant at 100°C (k1). - We need the temperature in Kelvin (T2 = 333.15 K). - We need the temperature coefficient (3).

3. Calculate the time it takes for the reaction to complete at 60°C (Time2): - We need the time it takes for the reaction to complete at 100°C (10 minutes). - We need the rate constant at 100°C (k1). - We need the rate constant at 60°C (k2).

Calculation at 150°C (423.15 K)

To calculate the time it takes for the reaction to complete at 150°C, we can follow the same steps as above, using the temperature in Kelvin (150°C = 423.15 K) and the temperature coefficient of 3.

Let's calculate the values:

1. Calculate the pre-exponential factor A. 2. Calculate the rate constant at 150°C (k2). 3. Calculate the time it takes for the reaction to complete at 150°C (Time2).

Calculation Results

Based on the calculations, the time it takes for the reaction to complete at different temperatures is as follows:

- At 60°C: 810 minutes - At 150°C: 2.47 seconds

Please note that these calculations assume the temperature coefficient remains constant over the temperature range and that the activation energy and pre-exponential factor are constant for the reaction.

I hope this helps! Let me know if you have any further questions.