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3 years ago

10

How many C-13 atoms are present, on average, in a 23000-atom sample of carbon?

1 answer:

barxatty [35]3 years ago

7 0

It contains 23000/13= 1769.23 C¹³ atoms

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Is food coloring in water a mixture or pure substance

kkurt [141]

Answer:

In this experiment, different solutions are made by mixing water with different colors and amounts of food coloring. Students should notice that once the water and colors are mixed together, the liquid looks the same throughout. It is a solution—a homogeneous mixture

Explanation:

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3 years ago

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385 J of heat are needed to heat a piece of aluminum from 22°C to 45°C. If the specific heat of Al is 0.90 J/g°C, what is the ma

VikaD [51]

Answer:

M of Al=33.09g or 0.0331kg

Explanation:

Heat Energy= specific heat*mass*change in temperature

H=M*C*T

make M subject of the formula

M=H/CT

M=685J/0.90J/g°C*(45°C-22°C)

M=685J/0.90J/g°C*23°C

M=685J/20.7J/g

M=33.09g or 0.0331kg

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3 years ago

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Tasya [4]

Answer:

<h2>A. Mercury's orbit is shorter than Earth</h2>

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3 years ago

Which of these outcomes is conclusive evidence that mixing sugar in water is a physical change?

lions [1.4K]

There is no molecular change

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3 years ago

Biacetyl, the flavoring that makes margarine taste "just like butter," is extremely stable at room temperature, but at 200°C it

Sholpan [36]

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:

$t__{1/2}}= \frac{0.693}{k}$

where;

k = constant

The formula can be re-written as:

$k = \frac{0.693}{t__{1/2}}$

$k = \frac{0.693}{9.0 min}$

$k = 0.077 min^{-1}$

Let the initial amount of butter flavor in the food be $(N_0)$ = 100%

Also, the amount of butter flavor retained at 200°C $(N_t)$ = 74%

The rate constant $k = 0.077 min^{-1}$

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

$\frac{N_t}{N_0}= -kt$

$t = - (\frac{1}{k}*In\frac{N_t}{N_0} )$

Substituting our values; we have:

$t = - (\frac{1}{0.077}*In\frac{74}{100} )$

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

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3 years ago