Science contest #1: How much is 1 mole?

Vitan · *Last edited by Vitan on 12 Apr 2011 11:08 am; edited 1 time in total*

Science contest #1
How much is 1 mole?
Science: Chemistry

PROBLEM: The mole is a unit of measurement for the amount of substance or chemical amount. I can surely say 1 mole of rice could feed whole world for a long time.
Calculate how thin would layer covering Earth made of 1 mole rice grains be, assumed 1 grain is 1 cube centimeter large and circumference of an Earth is 40000 km?

REWARD: Best calculation wins 100 Fg. DEADLINE: May 1st

Cancerous · Posted: 09 Apr 2011 04:28 am Post subject:

Surface area = 510,072,000 km2

510,072,000 km2 * (10 * 100 * 1000*)

= 510, 072, 000, 000, 000, 000 cm2

So you would need 510, 072, 000, 000, 000, 000 moles of rice.

Vitan · Posted: 09 Apr 2011 06:06 am Post subject:

Cancerous · Posted: 09 Apr 2011 06:14 am Post subject:

Oh...1cm?

thecrazykiller · Posted: 09 Apr 2011 03:52 pm Post subject:

Vitan · Posted: 10 Apr 2011 07:52 am Post subject:

Bump!

Cancerous · Posted: 10 Apr 2011 08:24 am Post subject:

(Grains of rice per layer) 510 072 000 000 000 000 / (population of earth) 6 770 000 000 000 = 75 342.9838 grains of rice per person.

There's about 3000 grains of rice in a bowl.

75 343/3000 = 75

So that's 75 bowls of rice per person.

Assuming it's rice for breakfast lunch and dinner, that's 25 days of rice supply.

"A long time" is hard, so I'll use a year as an example.

365/25 = 14.6

So that's 14.6 layers of rice.

1 layer = 1cm high
14.6cm deep each year.

Basi · Posted: 11 Apr 2011 03:02 pm Post subject:

Basi · Posted: 11 Apr 2011 03:38 pm Post subject:

ok here's the answer, i'm going to assume the circumference you provided is actually 40,000 instead of 40.000 and that it was just a typo

to know how much rice will form a layer to cover the entire world, you need to know what the entire world is. you have to calculate surface area from the given circumference first, a key step i sidestepped in my other post.

C= 2*pi*r, and we must solve for r (radius)
r = C/pi * 2; r = 6369 km

now with this radius, we must calculate surface area (SA)
SA = 4*pi*r^2
SA= 5.0952 x 10^8 cubic km

now cubic km to cubic cm
5.0952 x 10^8 cubic km x 1*10^15 = 5.0952 x 10^23 cubic cm = SA in cubic cm

6.02 x 10^23 cubic cm of rice / 5.0952 x 10^23 cubic cm SA= a layer that is 1.181 cm

and that's the answer, once again assuming a 40,000 circumference

Vitan · Posted: 13 Apr 2011 11:25 pm Post subject:

Cancerous · Posted: 13 Apr 2011 11:38 pm Post subject:

Why do you need to bump a stickied topic?
Lol.

Basi · Posted: 14 Apr 2011 09:48 am Post subject:

Why do u bump when the correct answer is already there o.O

for shits and giggles I just quadruple checked the math and formulas and it's all right

Vitan · Posted: 14 Apr 2011 03:48 pm Post subject:

I forgot topic is stikied and none of the answers is correct.

Basi · Posted: 14 Apr 2011 04:04 pm Post subject:

Vitan · Posted: 14 Apr 2011 04:13 pm Post subject:

Basi · Posted: 14 Apr 2011 04:25 pm Post subject:

1 mole of rice is 6.02 x 10^23 grains...

"6.02 x 10^23 cubic cm of rice / 5.0952 x 10^23 cubic cm SA= a layer that is 1.181 cm"

do you know how many cubic cm there are in this world lol? about a mole's worth

Basi · Posted: 29 Apr 2011 01:12 pm Post subject:

gave u 2 weeks, plenty o' time to discover the correct answer for yourself dear

Red

Basi

Red · Posted: 29 Apr 2011 02:30 pm Post subject:

118022.55367869634090873445317524 cubic cm thin