The best chem problem there is!!!!!?

Question

Knowing that there are 20 drops of water in a ml. How many atoms are there is a drop of water?? ATOMS! Not molecules!

Not that hard, is it?

Answer 1

Given:
20 Drops = 1 ml of water
1 Drop = How many atoms?

Problem is quite simple. It just need little thought and time.

In one molecule of water there is 1 atom of oxygen and 2 atom of hydrogen. Saying that lets calculate the number of molecules in 1 ml of water then, approximating drops of equal size, we can divide it by 20 to get the molecules in 1 drop of water.

I am asuming that you must know density of water (1g/ml) meaning that 1 ml of water = 1 g of water. Also you must be aware of what avogadro's number mean. Avogadro's number (6.022 x 10^23) is number of molecules in one mol of substance.

So calculate mol of water from 1 g of water.

1 mol of water = 18 g of water
?? = 1 g of water

1 g of water x 1 mol of water/ 18 g = .0556 mol of water

.0556 mol of water x (6.022 x 10^23 molecules of water / 1 mol) = 3.35 x 10^22 molecules of water in 1 g.
[by canceling mol of water you end up with molecules of water in 1g]

So in 1 ml of water there are 3.35 x 10^22 molecules of water. In 1 drop of water there would be 3.35 x 10^22/20 = 1.67 x 10^21 molecules of water in 1 drop.

But, in 1 molecule of water there are three atoms (1 atom of O and 2 atoms of H). So divide 1.67 x 10^21/3 = 5.58 x 10^20 which are the atoms of oxygen. And if you multiply that by two you get atoms of H since there are 2 H atoms for every O atom. So number of H atom would be 1.12 x 10 ^21 atoms of H

Answer 2

Alright!
20 drops→ 1,0 mL H2O
Lets hope it is just H2O and not drinkable water and lets assume 1,0 mL H2O = 1,0 g H2O
And then
1,0 g H2O*(6,022*10^23 H20 molecules/18g H2O)*(3 atoms/molecule H2O)*(1/20)= 5,1*10^21 atoms

Answer 3

By definition one gram is the mass of one ml (cubic centimeter) of water. The molar mass of water is 18.02 grams/mole so you multiply the one gram by the inverse of the molar mass (1/18.02 moles/gram) to get the moles of water in one ml.

Then divide the moles/ml by 20 drops/ml to get the moles in one drop.

Then multiply the moles/drop by 6.022 x 10^23 to get the molecules per drop.

Then multiply the number of molecules by 3 to get the number of atoms in a drop of water.

Simple.

Answer 4

1 drop of water = .05 ml of water
.05 ml of water = .05 grams of water
.05 grams of water = .0027 moles of water (18grams/mole)
.0027 moles of water = 1.63*10^21 molecules of water (6.023*10^23 molecules/mole)
1.63*10^21 molecules of water = 4.89*10^21 atoms (3 atoms/molecule)

Answer 5

1 gram/(18*20) * 6.023x10^23 (Avagodro's number)= num of molecules.

Personally I've found the mechanism in the pinocol-pinacolone rearrangement reaction much more fascinating.

Answer 6

N/60 where N = Avogadro's #