Mass of oxygen in 2.5 × 10² g of CaCO₃

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Homework Statement


What would be the mass of oxygen in 2.5 x 102 g in CaCO3?
Given:
Mass 2.5 x 102
Molar Mass of CaCO3 which is 100.09 g/mol.

Homework Equations


mo=molar mass x number of o

The Attempt at a Solution


mo=100.09 g/mol x 3
mo=300.27 g of oxygen

Can someone tell me if I got this right? Thank you.
 
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Sace Ver said:

Homework Statement


What would be the mass of oxygen in 2.5 x 102 g in CaCO3?
Given:
Mass 2.5 x 102
Molar Mass of CaCO3 which is 100.09 g/mol.

Homework Equations


mo=molar mass x number of o

The Attempt at a Solution


mo=100.09 g/mol x 3
mo=300.27 g of oxygen

Can someone tell me if I got this right? Thank you.
If you start with 250 g of CaCO3, how can you have 300.27 g of oxygen?
 
Sace Ver said:

Homework Statement


What would be the mass of oxygen in 2.5 x 102 g in CaCO3?
Given:
Mass 2.5 x 102
Molar Mass of CaCO3 which is 100.09 g/mol.

Homework Equations


mo=molar mass x number of o

The Attempt at a Solution


mo=100.09 g/mol x 3
Here, you are assuming that all 100 g/mol is oxygen, which it is clearly not.

You need to figure out how many moles of CaCO3 there are in 250 g of the substance.
 
Assuming one mole of CaCO3 - how many moles of O (atomic oxygen)?
 
SteamKing said:
Here, you are assuming that all 100 g/mol is oxygen, which it is clearly not.

You need to figure out how many moles of CaCO3 there are in 250 g of the substance.
And then divide by 3 bc there is 3 atoms of oxygen?
 
Sace Ver said:
And then divide by 3 bc there is 3 atoms of oxygen?
There will be 3 moles of oxygen atoms in each mole of CaCO3.