Molar mass: Difference between revisions

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[[Category:Done 2015-06-01]]  
[[Category:Done 2020-01-31]]
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[[fr:Masse molaire]]
<onlyinclude>'''Molar mass''' (M) is a physical property, defined as the [[mass]] of a given [[element]] or [[molecule]] per [[mole]] of that substance. Since a mole is defined as the amount of a substance and substances have different masses, each element or molecule will have a different molar mass.</onlyinclude> For example, if someone has a dozen bricks and another person has a dozen feathers, they have the same amount of their substance, but a vastly different total mass. However when talking about [[mole]]s, instead of only having a dozen, there is in fact 6.022141 x 10<sup>23</sup> of a given substance in a mole (known as [[Avogadro's number]]). This comparison is seen below:  
<onlyinclude>'''Molar mass''' (M) is a physical property, defined as the [[mass]] of a given [[element]] or [[molecule]] per [[mole]] of that substance. Since a mole is defined as the amount of a substance and substances have different masses, each element or molecule will have a different molar mass.</onlyinclude> For example, if someone has a dozen bricks and another person has a dozen feathers, they have the same amount of their substance, but a vastly different total mass. However when talking about [[mole]]s, instead of only having a dozen, there is in fact 6.022141 x 10<sup>23</sup> of a given substance in a mole (known as [[Avogadro's number]]). This comparison is seen below:  


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In [[SI]] units, the molar mass is given by [[kilogram|kg]]/[[mole|mol]], however by convention the molar mass is expressed in units of [[gram|g]]/mol. The molar mass of any element or molecule is given by the sum of the [[atomic weight]]s multiplied by 1 g/mol. A list of some molar masses can be seen below.<ref>M. Wieser, ''Atomic Weights of the Elements 2005'' [Online], Available: http://www.iupac.org/publications/pac/2006/pdf/7811x2051.pdf</ref>  
In [[SI]] units, the molar mass is given by [[kilogram|kg]]/[[mole|mol]], however by convention the molar mass is expressed in units of [[gram|g]]/mol. The molar mass of any element or molecule is given by the sum of the [[atomic weight]]s multiplied by 1 g/mol. A list of some molar masses can be seen below.<ref>M. Wieser, ''Atomic Weights of the Elements 2005'' [Online], Available: http://www.iupac.org/publications/pac/2006/pdf/7811x2051.pdf</ref>  


{| class="wikitable floatleft"  
{| class="wikitable floatright"  
|-
|-
! Element/Molecule !! Molar Mass (M)
! Element/Molecule !! Molar Mass (M)
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By knowing the molar mass of a substance, having any mass of that substance allows one to know how many moles of it they have. This is given by the equation  
By knowing the molar mass of a substance, having any mass of that substance allows one to know how many moles of it they have. This is given by the equation  


<center><m>n=\frac{m}{M}</m></center>
<center><math>n=\frac{m}{M}</math></center>


where:
where:


<m>m</m> is the mass of the substance in grams
<math>m</math> is the mass of the substance in grams<br/>
<m>M</m> is the molar mass of the substance
<math>M</math> is the molar mass of the substance<br/>
<m>n</m> is the amount in moles of that substance
<math>n</math> is the amount in moles of that substance
<br/><br/>
 
==For Further Reading==
*[[Carbon dioxide]]
*[[Molecule]]
*[[Mole]]
*[[Chemical]]
*Or explore a [[Special:Random|random page]]
 
==References==
==References==
{{reflist}}
{{reflist}}
[[Category:Uploaded]]
[[Category:Uploaded]]

Latest revision as of 00:03, 27 September 2021

Molar mass (M) is a physical property, defined as the mass of a given element or molecule per mole of that substance. Since a mole is defined as the amount of a substance and substances have different masses, each element or molecule will have a different molar mass. For example, if someone has a dozen bricks and another person has a dozen feathers, they have the same amount of their substance, but a vastly different total mass. However when talking about moles, instead of only having a dozen, there is in fact 6.022141 x 1023 of a given substance in a mole (known as Avogadro's number). This comparison is seen below:

1 dozen = 12 objects
1 mol = 6.022141 x 1023 objects

In SI units, the molar mass is given by kg/mol, however by convention the molar mass is expressed in units of g/mol. The molar mass of any element or molecule is given by the sum of the atomic weights multiplied by 1 g/mol. A list of some molar masses can be seen below.[1]

Element/Molecule Molar Mass (M)
Hydrogen (H) 1.00794 g/mol
Carbon (C) 12.0107 g/mol
Iron (Fe) 55.845 g/mol
Uranium 238.02891 g/mol
Water (H2O) 18.01528 g/mol
Carbon dioxide (CO2) 44.0095 g/mol

By knowing the molar mass of a substance, having any mass of that substance allows one to know how many moles of it they have. This is given by the equation

[math]n=\frac{m}{M}[/math]

where:

[math]m[/math] is the mass of the substance in grams
[math]M[/math] is the molar mass of the substance
[math]n[/math] is the amount in moles of that substance

For Further Reading

References

  1. M. Wieser, Atomic Weights of the Elements 2005 [Online], Available: http://www.iupac.org/publications/pac/2006/pdf/7811x2051.pdf