Let's begin with the information we want and the information we have.
We want: -The number of atoms of oxygen in 16.00 grams of water (H2O)
We have: - Ratio of oxygen atoms in each molecule of water (From formula, it's 1 oxygen to 2 hydrogen)
- Atomic masses of oxygen and hydrogen
- From avogadro's number, the number of atoms in one unit of moles is 6.02 x 10²³
To solve this, we first find the molar mass of the molecule in question, water, by adding up the atomic masses of each atom
1 Oxygen (16.0 g) + 2 Hydrogen (1.0 g + 1.0 g) = 18.0 g per mol of H2O (water)
The value we obtained here is the mass of water within one unit of what we call a mol. A mol is just a useful conversion factor for a variety of different applications that I will not go into here since you should know.
Putting all this together with what we have it is all just a big stoichiometry problem
(Given mass) x (Molar Mass) x (Ratio) x (Avogadro's number)
# of moles of O in H2O = 16.00 g H2O x 1 mol/18.0g x 1 O/1H2O x 6.02 x 10²³ atoms/1 mol = Answer
We want: -The number of atoms of oxygen in 16.00 grams of water (H2O)
We have: - Ratio of oxygen atoms in each molecule of water (From formula, it's 1 oxygen to 2 hydrogen)
- Atomic masses of oxygen and hydrogen
- From avogadro's number, the number of atoms in one unit of moles is 6.02 x 10²³
To solve this, we first find the molar mass of the molecule in question, water, by adding up the atomic masses of each atom
1 Oxygen (16.0 g) + 2 Hydrogen (1.0 g + 1.0 g) = 18.0 g per mol of H2O (water)
The value we obtained here is the mass of water within one unit of what we call a mol. A mol is just a useful conversion factor for a variety of different applications that I will not go into here since you should know.
Putting all this together with what we have it is all just a big stoichiometry problem
(Given mass) x (Molar Mass) x (Ratio) x (Avogadro's number)
# of moles of O in H2O = 16.00 g H2O x 1 mol/18.0g x 1 O/1H2O x 6.02 x 10²³ atoms/1 mol = Answer
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To solve this problem you must first calculate the molar mass of H20...
O = 16g/mol
H = 1g/mol
H20 = 18g/mol
Then, you calculate the number of moles of the molecule H20
16/18 = 0.89 moles H20
>>These last two steps can be done in any order:
Then you must realize that there is 1 Oxygen atom per molecule of water
So 0.89 moles H20 contains 0.89 moles of Oxygen atoms
So then you multiply this by Avogadro's number (6.02x10^23 formula units(formula units means molecules or atoms, whatever you're currently working with) per mole)
0.89x(6.02x10^23)=5.36x10^23 Atoms of Oxygen
O = 16g/mol
H = 1g/mol
H20 = 18g/mol
Then, you calculate the number of moles of the molecule H20
16/18 = 0.89 moles H20
>>These last two steps can be done in any order:
Then you must realize that there is 1 Oxygen atom per molecule of water
So 0.89 moles H20 contains 0.89 moles of Oxygen atoms
So then you multiply this by Avogadro's number (6.02x10^23 formula units(formula units means molecules or atoms, whatever you're currently working with) per mole)
0.89x(6.02x10^23)=5.36x10^23 Atoms of Oxygen
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5.352 * 10^23 atoms are present
in 18 gm of water,16 gm of O2 present
thus in 16 gm of water, 16 * 16/18 = 14.22 gm of O2 present
in 16 gm of O2 , 6.022 * 10^23 atoms are present
thus in 14.22 gm , 6.022 * 10^23 * 14.22 /16
= 5.352 * 10^23 atoms are present
in 18 gm of water,16 gm of O2 present
thus in 16 gm of water, 16 * 16/18 = 14.22 gm of O2 present
in 16 gm of O2 , 6.022 * 10^23 atoms are present
thus in 14.22 gm , 6.022 * 10^23 * 14.22 /16
= 5.352 * 10^23 atoms are present
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go grams to moles and then moles to atoms (avogadro's number). I'm not gonna do it for you as it's simple and a good calculation for you to learn.
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H2O = 1 oxygen atom..
but if you want to know the number of moles,
here's the solution
1 H2O = 18 grams/mole
16 grams H2O = 18 grams/mole H2O
16 grams H2O/ 18 grams H2O = moles H2O
0.89 moles H2O
but if you want to know the number of moles,
here's the solution
1 H2O = 18 grams/mole
16 grams H2O = 18 grams/mole H2O
16 grams H2O/ 18 grams H2O = moles H2O
0.89 moles H2O