# Is a mole (mol) a base unit or a dimensionless quantity?

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#1
Is confusion to me.
0
7 years ago
#2
(Original post by Mullah.S)
Is confusion to me.
According to SI it is a base (fundamental) unit

http://en.wikipedia.org/wiki/SI_base_unit
0
7 years ago
#3
A mole is just a number. It is the number of molecules that is equal in mass (in grams) to it's relative molecular mass.
e.g. 1 mole of 12C (carbon-12 isotope) atoms is equal to 12 grams.

This number is known as Avagadro's constant.
0
7 years ago
#4
(Original post by JMaydom)
A mole is just a number. It is the number of molecules that is equal in mass (in grams) to it's relative molecular mass.
e.g. 1 mole of 12C (carbon-12 isotope) atoms is equal to 12 grams.

This number is known as Avagadro's constant.
JMaydom!!!!!

(edit)

Lorenzo Romano Amedeo Carlo Avogadro di Quaregna e di Cerreto would turn in his grave ....
4
7 years ago
#5
(Original post by Mullah.S)
Is sounding like mere mark scoring definition, i am wanting know whether is dimensionless quantity or a base unit.

thank you anyway
I wrote that it is a base unit in my post above!
0
7 years ago
#6
(Original post by Mullah.S)
Is confusion to me.
A mole is an SI unit I think, definitely has dimensions.
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#7
(Original post by charco)
According to SI it is a base (fundamental) unit

http://en.wikipedia.org/wiki/SI_base_unit

ok thanks.

But my question is being, if is base unit and not dimensionless quantity, is meaning it is having dimension. What is the dimension of the base unit mole? (i.e what is the base quantity)

(Original post by charco)
I wrote that it is a base unit in my post above!
oh i am seeing only know, thankyou

(Original post by charco)
JMaydom!!!!!

Amedeus would turn in his grave ....
Amedeo*

to much mozart

0
7 years ago
#8
It's just an amount of something.
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#9
(Original post by The_Last_Melon)
It's just an amount of something.

what does amount meaning if it is not dimensionless quantity?
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7 years ago
#10
(Original post by Mullah.S)
what does amount meaning if it is not dimensionless quantity?
moles is a dimension just like metres, yards, litres and volts are. just remember n moles is equivalent to n*6.0221415e+23 molecules. i think they use it because it's much more useful to know than litres which is the amount of space the substance takes up which is very dependant on intermolecular forces and greatly varies depending on the molecule.

i only did AS chemistry though so take my advice with a pinch of salt

EDIT: also two more things to remember:

1 mole of any substance has a mass equal to the molecular mass of that substance in grams. so 1 mole of carbon (molecular mass 12) has a mass of 12g, 1 mole of CO2 has a mass equal to the molecular mass of carbon + 2* the molecular mass of oxygen in grams.

also I think but i'm not sure that a mole of any gas has the same volume as a mole of any other gas. need someone to confirm this though.
0
7 years ago
#11
It's just a standard unit of measurement. It just lets scientist know how many atoms are in something (usually a solution). It isn't dimensionless, a mole can physically be measured.

Best way to think about it:
There are 6.023 x 10^23 atoms in 1g of hydrogen. Carbon is 12 times heavier than hydrogen so 6.023 x 10^23 atoms in carbon will be 12g. If hydrogen is the standard, the number of grams in a mole of any element can be figured out (14g of nitrogen makes a mole, 16g of oxygen makes a mole etc...)
2
#12
(Original post by Iamyourfather)
It's just a standard unit of measurement. It just lets scientist know how many atoms are in something (usually a solution). It isn't dimensionless, a mole can physically be measured.

Best way to think about it:
There are 6.023 x 10^23 atoms in 1g of hydrogen. Carbon is 12 times heavier than hydrogen so 6.023 x 10^23 atoms in carbon will be 12g. If hydrogen is the standard, the number of grams in a mole of any element can be figured out (14g of nitrogen makes a mole, 16g of oxygen makes a mole etc...)
Oh, i am thankyou.

i was thinking mole is just synonym of avagadro number (which is a dimensionless quantity). so one mole of a thing does not meaning 6.02*10^23 of the things.
0
7 years ago
#13
(Original post by charco)
JMaydom!!!!!

(edit)

Lorenzo Romano Amedeo Carlo Avogadro di Quaregna e di Cerreto would turn in his grave ....
grrrrr

Cracking full name...
0
7 years ago
#14
(Original post by Mullah.S)
Oh, i am thankyou.

i was thinking mole is just synonym of avagadro number (which is a dimensionless quantity). so one mole of a thing does not meaning 6.02*10^23 of the things.
Thb, I wasn't entirely sure what you meant by 'dimensionless'.
Based on what was said just know that 6.022x10^23 (ignore the number I write earlier) atoms is mole.
0
7 years ago
#15
I think it might be dimensionless as a "mole" of something is just 6.02 x 10^-23 of something, it's just a number. And I think it is therefore dimensionless as it's just a number of things.

Like one mole of electrons is 6.02 x 10^-23 electrons, and one mole of hedgehogs is just 6.02 x 10^-23 hedgehogs... It is a SI unit but I believe it is also dimensionless, so it's both.
0
#16
(Original post by holliebass)
I think it might be dimensionless as a "mole" of something is just 6.02 x 10^-23 of something, it's just a number. And I think it is therefore dimensionless as it's just a number of things.

Like one mole of electrons is 6.02 x 10^-23 electrons, and one mole of hedgehogs is just 6.02 x 10^-23 hedgehogs... It is a SI unit but I believe it is also dimensionless, so it's both.
unit and dimensionless are be mutually exclusive

is like saying something is both haraam and halaal at the same time
0
7 years ago
#17
(Original post by Mullah.S)
unit and dimensionless are be mutually exclusive

is like saying something is both haraam and halaal at the same time
Yeah I was wrong:

"According to the SI, the mole is not dimensionless, but has its very own dimensions, namely "amount of substance", comparable to other dimensions such as mass and luminous intensity"
0
2 years ago
#18
It is a base unit.
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