Question

Here is my question:
diameter of circle is 6.5cm
area of circle is 33.16cm

I need to know howmany soap molecules are in the crude circle formed after I dropped one drop of diluted dish detergent into a petri dish filled with water and cinnamon sprinkled on top. The detergent pushed the cinnamon away leaving a circle....I measured the circle and got 6.5cm. ThenI calculated the area of the circle and got 33.16cm.

It states I need to use the info:
1 x 10^14 nm^2 for every 1 cm^2 and
the area of a soap molecule is 0.210nm^2.

I do not know how to figure out the answer.

Answer 1

If the Area of Circle (petri Dish) is 33.16cm^2.
Statement if 1*10^14 nm^2 represent 1 cm^2
\[1*10^14-->1\]
\[x--->33.6\]
Cross Multiplication to get what 33.6 cm^2 represent in nm^2. The area of soap molecule equals 0.210nm^2 we have 33.6*1*10^14 the whole so how many molecule of soap can fit into the pedri dish so it would be 33.16*1*10^14/0.210

Answer 2

Hi.....so I would multiply 33.6 or 33.16?

Answer 3

sorry 33.16

Answer 4

so that leaves me with a HUGE number? Yes?

Answer 5

no worries....just checking!! :)

Answer 6

33.16 x 1 x 10^14? Yes?

Answer 7

Yes thats right

Answer 8

then divide that number by 0.210?

Answer 9

so I would add 12 zeros, because there are already two places to the right of the decimal?

Answer 10

15790476190476190.4761904761904762 Round This Number

Answer 11

1.57*10^13

Answer 12

so that is the number of soap molecules in the crude circle?

Answer 13

Exactly.

Answer 14

THANK YOU SO MUCH!!!! I appreciate your help more than I can tell you!!!!

Answer 15

one more quick question....before you go....

Answer 16

is the area of a circle written 33.16cm^2? Or is the diameter of the circle written 6.5cm^2? I know one of them is squared.

Answer 17

Diameter is written as 6.5cm and area is written in cm^2 but i think you forgot to write the unit properly. thats okay i hope that help your most welcome if you got any doubts about the problem feel free to ask

Answer 18

Okay!! Got it and will fix it!!! Awesome....thank you again!!! I left a comment under your profile! Have a good night!!

Answer 19

your most welcome, good night :)

Answer 20

:)