Surface area of N spherical droplets?

In summary, the conversation revolves around finding the total surface area of N spherical droplets with a known radius and volume. The problem seems to be understanding how to relate the calculated surface area of each atom to the total surface area of all the droplets. A helpful hint is given to consider the surface area of multiple droplets to find a pattern.
  • #1
saber1357
67
1
I have the following problem
Assume that 30.0 cm^3 of gasoline is atomized into N spherical droplets, each with a radius of 2.00 x 10^-3 m. What is the total surface area of these N spherical droplets?
I calculated the surface area of each atom to be 5x10^-9 m^2.
I also calculated the volume of each droplet to be 3.35x10^-14 m^3.
However, my mind can't seem to relate these numbers to my task. Any help is GREATLY appreciated.
 
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  • #2
First things first. Next time, please post this in the correct Homework Help section. This forum is for general academic advice not pertaining homework problems.:smile:

Ok, so you know you have N atoms each with a known surface area. If you know the surface area of one, what is stopping you from finding the total surface area of all of them?

HINT: What would be the surface area of 2 droplets? 3? 4? ...
 
  • #3


I can understand your confusion and I am happy to help you with this problem. To calculate the total surface area of N spherical droplets, we need to use the formula for the surface area of a sphere, which is 4πr^2, where r is the radius of the sphere. In this case, the radius of each droplet is 2.00 x 10^-3 m, so the surface area of each droplet would be 4π(2.00 x 10^-3)^2 = 5.03 x 10^-5 m^2.

To find the total surface area of N droplets, we need to multiply the surface area of one droplet by the number of droplets, which in this case is N. So, the total surface area would be 5.03 x 10^-5 m^2 x N = 5.03 x 10^-5 N m^2.

In order to find the value of N, we can use the given volume of gasoline, 30.0 cm^3, and the volume of each droplet, 3.35 x 10^-14 m^3. We know that 1 cm^3 is equal to 1 x 10^-6 m^3, so we can convert the given volume to cubic meters: 30.0 cm^3 = 30 x 10^-6 m^3. Now, we can set up a proportion to find the value of N:

30 x 10^-6 m^3 / 3.35 x 10^-14 m^3 = N / 1
Solving for N, we get N = 8.95 x 10^7 droplets.

Substituting this value of N into our previous equation for total surface area, we get:
5.03 x 10^-5 m^2 x 8.95 x 10^7 = 4.50 x 10^3 m^2

Therefore, the total surface area of N spherical droplets with a radius of 2.00 x 10^-3 m is 4.50 x 10^3 m^2. I hope this helps you understand the problem better and how to approach it mathematically. If you have any further questions, please do not hesitate to ask.
 

1. What is the formula for calculating the surface area of N spherical droplets?

The formula for calculating the surface area of N spherical droplets is 4πr2N, where r is the radius of the droplet and N is the number of droplets.

2. How does the surface area of N spherical droplets change with increasing number of droplets?

The surface area of N spherical droplets increases with increasing number of droplets. This is because more droplets means more surface area is exposed.

3. Is there a limit to the number of droplets that can be present in a given volume?

Yes, there is a limit to the number of droplets that can be present in a given volume. This is due to the fact that as the number of droplets increases, they will eventually start touching each other and form a continuous layer, limiting the number of droplets that can fit in the volume.

4. How does the surface area of N spherical droplets compare to that of a single larger droplet with the same volume?

The surface area of N spherical droplets will always be greater than that of a single larger droplet with the same volume. This is because the surface area of a sphere increases as the radius increases, so multiple smaller droplets will have a larger combined surface area compared to a single larger droplet with the same volume.

5. How is the surface area of N spherical droplets related to the stability of a liquid mixture?

The surface area of N spherical droplets is directly related to the stability of a liquid mixture. This is because a larger surface area means there is more surface tension between the droplets, making it more difficult for them to merge or coalesce. Therefore, a larger surface area of N spherical droplets indicates a more stable liquid mixture.

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