How to find moles of O in CO molecule?

[Indranil]

Homework Statement

If CO = 10 moles, then how to find moles of O in CO molecule?

Homework Equations

If CO = 10 moles, then how to find moles of O in CO molecule?

The Attempt at a Solution

I don't know how to proceed

 

[jedishrfu]

Read the definition of a mole here:

https://en.wikipedia.org/wiki/Mole_(unit)

and you should be able to work this out.

Its like the old trick question of which is heavier a pound of feathers or a pound of rocks.

In the future, please provide more than I don't know as your attempt. You should research your problem and not just sit there confused. There is a way out of every maze and you can find it if you try.

 

[Indranil]

Read the definition of a mole here:

https://en.wikipedia.org/wiki/Mole_(unit)

and you should be able to work this out.

Its like the old trick question of which is heavier a pound of feathers or a pound of rocks.

In the future, please provide more than I don't know as your attempt. You should research your problem and not just sit there confused. There is a way out of every maze and you can find it if you try.

From the given link, I cam to know that
2 H2 + O2 → 2H2O implies that 2 mol dihydrogen (H2) and 1 mol dioxygen (O2) react to form 2 mol water (H2O). From this concept, I can write
1 mol C and 1-mole O2 form 1 mole of CO but how to calculate moles of O if CO = 10 moles already?

 

[Merlin3189]

From the given link, I cam to know that
2 H2 + O2 → 2H2O implies that 2 mol dihydrogen (H2) and 1 mol dioxygen (O2) react to form 2 mol water (H2O). From this concept, I can write
1 mol C and 1-mole O2 form 1 mole of CO but how to calculate moles of O if CO = 10 moles already?

I agree with the water, but what is the equation for C and O₂?

When you've sorted that,
if 2 mole H₂ and 1 mole o₂ makes 2 mole H₂O,
then how many mole of each is needed to make 10 mole H₂0 ? It's just proportion.

 

[jedishrfu]

A simpler set of questions are:

If I have 1 molecule of $CO$ then I know I have 1 atom of $C$ and so how many atoms of $O$ do I have?

If I have 2 molecules of $CO$ then I know I have 2 atoms of $C$ and so how many atoms of $O$ do I have?

If the $O$ atoms combine into $O_2$ then how many $O_2$ molecules do I have?

Basically moles are a count of the number of molecules or atoms in the sample.

Like when I say I have 1 dozen eggs I know I have 12 eggs.

When I say I have 1 mole of eggs then I know I have $6.022 x 10^{23}$ (Avogadros number) of eggs.

https://en.wikipedia.org/wiki/Avogadro_constant

The next question why are mole calculations so important to chemists?

http://chemistry.bd.psu.edu/jircitano/mole.html

https://www.khanacademy.org/science...-to-the-atom/v/the-mole-and-avogadro-s-number

 

[Indranil]

I agree with the water, but what is the equation for C and O₂?

When you've sorted that,
if 2 mole H₂ and 1 mole o₂ makes 2 mole H₂O,
then how many moles of each is needed to make 10 mole H₂0 ? It's just proportion.

It should be C + O2 = 2CO
10 mol H2O and 5 mol O2 make 10 mol H2O
10 H2 + 5 O2 = 10 H2O

 

[Indranil]

A simpler set of questions are:

If I have 1 molecule of $CO$ then I know I have 1 atom of $C$ and so how many atoms of $O$ do I have?

If I have 2 molecules of $CO$ then I know I have 2 atoms of $C$ and so how many atoms of $O$ do I have?

If the $O$ atoms combine into $O_2$ then how many $O_2$ molecules do I have?

Basically moles are a count of the number of molecules or atoms in the sample.

Like when I say I have 1 dozen eggs I know I have 12 eggs.

When I say I have 1 mole of eggs then I know I have $6.022 x 10^{23}$ (Avogadros number) of eggs.

https://en.wikipedia.org/wiki/Avogadro_constant

The next question why are mole calculations so important to chemists?

http://chemistry.bd.psu.edu/jircitano/mole.html

https://www.khanacademy.org/science...-to-the-atom/v/the-mole-and-avogadro-s-number

In 1 molecule of CO, I have 1 atom of C and 1 atom of O.
so 2 molecules of CO, I have 2 atoms of C and 2 atoms of O.
10 molecules of CO, I have 10 atoms of C and 10 atoms of O. Am I right?
From your context, I have a doubt.
What do you mean by 1 atom of C? Does it mean 1 mol of C atoms?

 

[Merlin3189]

Right. 1 C + 1 O₂ = 2 CO so scale this up to give 10 CO

 

[Borek]

What do you mean by 1 atom of C? Does it mean 1 mol of C atoms?

1 atom of C is 1 atom of C, 1 mole of atoms of C is 1 mole (6.02×10²³) of atoms of C. Typically when we say "1 mole of C" we mean 1 mole of atoms of C.

 

[jedishrfu]

In 1 molecule of CO, I have 1 atom of C and 1 atom of O.
so 2 molecules of CO, I have 2 atoms of C and 2 atoms of O.
10 molecules of CO, I have 10 atoms of C and 10 atoms of O. Am I right?
From your context, I have a doubt.
What do you mean by 1 atom of C? Does it mean 1 mol of C atoms?

I meant one atom of C or more properly one Carbon (C) atom. Your extension to 1 mole is okay since you're now understanding a mole to be a specific number of carbon atoms

There are no doubts only questions. In american english, doubt means to not believe something is true which can be taken to mean that you think the person is not being truthful.

 

[jedishrfu]

The whole point of moles is understand how to create compounds like a cooking recipe.

I take one cup of carbon and 1 cup of oxygen to make one cup of carbon-monoxide (CO)

However in the real world using cups or using weights of elements or compounds will produce wasted left-over materials in the chemical process. Chemists discovered that if they can mix ingredients by numbers of atoms or molecules that ideally there will be no waste and so the mole was invented, atomic weights were measured and a whole lot of molarity and molality problems were created for students of chemistry and science.

 

[Indranil]

I meant one atom of C or more properly one Carbon (C) atom. Your extension to 1 mole is okay since you're now understanding a mole to be a specific number of carbon atoms

There are no doubts only questions. In american english, doubt means to not believe something is true which can be taken to mean that you think the person is not being truthful.

Could you be more specific on ''one carbon atom and one mole of carbon atoms?'' what is the difference between them? Could you clarify it, please?

 

[jedishrfu]

My suggestion is to go watch the Khan Academy video.

 

[Merlin3189]

I think I see your point. These chemical equations show the number of each species in a reaction. They may be atoms or molecules.
For many elements an atom is also considered a molecule, but for many gaseous elements molecules have two atoms - which is why we write O₂ rather than 2 O.when elemental Oxygen occurs in an equation.

So you are correct to say

...
10 molecules of CO, I have 10 atoms of C and 10 atoms of O. Am I right? Yes.

But since oxygen molecules have two atoms, you get only 5 molecules of oxygen.

For the difference between molecules and moles you probably need
to read up on moles (and maybe Avogadro's constant.)

Basically, your equations show the number of atoms and molecules involved in the smallest unit of the reaction. Like an atom of carbon and an atom of oxygen gives a molecule of CO. But this is repeated billions of billions of billions ... of times when you react perceptible amounts of material together.

What we are usually interested in, is the mass or volume of reagents needed or produced. For this it is convenient to talk about moles.
A mole is the relative molecular mass of the substance times 1 g.
Hydrogen has atomic mass 1, molecular mass 2, so a mole of hydrogen is 2 g.
Carbon has atomic mass 12, (commonly*) molecular mass 12, so a mole of carbon is 12 g
Oxygen has atomic mass 16, molecular mass 32, so a mole of oxygen is 32 g


The actual number of atoms or molecules in the mole is not so important as the fact that 1 mole of anything contains the same number of molecules as 1 mole of anything else.

(* molecular weight is not as clear cut as you might hope! But so long as you are consistent, there is no problem.)

Edit: Blow me down! I've just reread Borek's post. This is probably a more accurate representation of the modern mole than my version. But I'd suggest that coming to it through the flawed gram-molecule may be easier to start with?

 

[Indranil]

1 atom of C is 1 atom of C, 1 mole of atoms of C is 1 mole (6.02×10²³) of atoms of C. Typically when we say "1 mole of C" we mean 1 mole of atoms of C.

1 atom of C means 1 atom of Avogadro's numbers of C = 1 atom of 6.023 X 10^23 numbers of C atoms?

 

[jedishrfu]

@Indranil please take some time to watch the Khan Academy video it should clarify much of your confusion.

Moles is all about numbers of atoms and molecules nothing more. To find the number of atoms we need the atomic weight of an atom or molecule so we can convert the measured weight of a compound into moles and from there into new compounds through chemical processes.

As noted earlier, 1 mole of CO is composed of 1 mole of carbon and 1 mole of oxygen atoms. If the oxygen combines into O2 then the 1mole of oxygen atoms becomes 1/2 mole of O2 molecules.

 

[Indranil]

Does 1 C atom mean a single C atom of 6.023 X 10^23C atoms = 1 C atom of Avogadro's number of C atoms = 1 C atom of 6.023 X 10^23 numbers of C atoms?
Does 1 mole of C atoms mean Avogadro's number of C atoms = 6.023 X 10^23 numbers of C atoms?
I am confused. What is the difference between them (1 C atom and 1 mole of C atoms)? Could you clarify it, please?

 

[Borek]

Right. 1 C + 1 O₂ = 2 CO so scale this up to give 10 CO

Beware, this is not balanced.

 

[jedishrfu]

Yes 1 C atom means one atom.

Yes 1mole Of C atoms means $6.023x10^{23}$ C atoms.

 

[Merlin3189]

Yes, sorry. Not sure how I mdid that (though when you're counting 10²³ atoms, it's hardly surprising if you miss the odd one.)

 

[Indranil]

Beware, this is not balanced.

10C + 5O2 = 10CO

 

[jedishrfu]

Yes, I think you got it. The O2 twist always tricks students. I think it fooled me when I took chem many decades ago.