Biacetyl, the flavoring that makes margarine taste "just like butter," is extremely stable at room temperature, but at 200°C it undergoes a first-order breakdown with a half-life of 9.0 min. An industrial flavor-enhancing process requires that a butter-flavored food be heated briefly at 200°C. How long can the food be heated at this temperature and retain 74% of its buttery flavor?

Respuesta :

Answer:

3.91 minutes

Explanation:

Given that:

Biacetyl breakdown with a half life of 9.0 min after undergoing first-order reaction;

As we known that the half-life for first order is:

[tex]t__{1/2}}= \frac{0.693}{k}[/tex]

where;

k = constant

The formula can be re-written as:

[tex]k = \frac{0.693}{t__{1/2}}[/tex]

[tex]k = \frac{0.693}{9.0 min}[/tex]

[tex]k = 0.077 min^{-1}[/tex]

Let the initial amount of butter flavor in the food be [tex](N_0)[/tex] = 100%

Also, the amount of butter flavor retained at 200°C [tex](N_t)[/tex]= 74%

The rate constant [tex]k = 0.077 min^{-1}[/tex]

To determine how long can the food be heated at this temperature and retain 74% of its buttery flavor; we use the formula:

[tex]\frac{N_t}{N_0}= -kt[/tex]

[tex]t = - (\frac{1}{k}*In\frac{N_t}{N_0} )[/tex]

Substituting our values; we have:

[tex]t = - (\frac{1}{0.077}*In\frac{74}{100} )[/tex]

t = 3.91 minutes

∵ The time needed for the food to be heated at this temperature and retain 74% of its buttery flavor is 3.91 minutes

3.91 minutes is the time the food be heated at this temperature and retain 74% of its buttery flavor.

What is half life time of a reaction?

Half life time is the required time when the concentration of reactant left with the half of the initial concentration.

Given half life time for the first order reaction of the breakdown of Biacetyl = 9 min.

We know that half life time for 1st order reaction is written as:
t = 0.693/k, where

k = rate constant

k = 0.693/9 = 0.077 min⁻¹

Now, required time for the food be heated at this temperature can be calculated by using the rate equation of first order reaction as:

T = -(1/k×ln[N/N₀]), where

N = initial amount of butter flavor in food = 100% (given)

N₀ = amount of butter flavor retained food = 74% (given)

Now putting all these values in the above equation, we get

T = - (1/0.077 × ln[74/100])

T = 3.91 minutes

Hence, 3.91 minutes is the time the food be heated at this temperature.

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https://brainly.com/question/14936355