Molar mass: Difference between revisions
J.williams (talk | contribs) m (1 revision imported) |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Category:Done | [[Category:Done 2018-05-18]] | ||
<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: | <translate> | ||
<!--T:1--> | |||
<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: | |||
<!--T:2--> | |||
<center>1 dozen = 12 objects</center> | <center>1 dozen = 12 objects</center> | ||
<center>1 mol = 6.022141 x 10<sup>23</sup> objects</center> | <center>1 mol = 6.022141 x 10<sup>23</sup> objects</center> | ||
<!--T:3--> | |||
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> | ||
<!--T:4--> | |||
{| class="wikitable floatleft" | {| class="wikitable floatleft" | ||
|- | |- | ||
| Line 24: | Line 29: | ||
|} | |} | ||
<!--T:5--> | |||
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>< | <!--T:6--> | ||
<center><math>{n}=\frac{m}{M}</math></center> | |||
<!--T:7--> | |||
where: | where: | ||
*'''m''' is the mass of the substance in grams | |||
*'''M''' is the molar mass of the substance | |||
*'''n''' is the amount in moles of that substance | |||
<br/><br/> | <br/><br/> | ||
==References== | ==References== <!--T:8--> | ||
{{reflist}} | {{reflist}} | ||
</translate> | |||
<languages /> | |||
[[Category:Uploaded]] | [[Category:Uploaded]] | ||
Revision as of 22:20, 11 May 2018
<translate> 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:
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
where:
- m is the mass of the substance in grams
- M is the molar mass of the substance
- n is the amount in moles of that substance
References
- ↑ M. Wieser, Atomic Weights of the Elements 2005 [Online], Available: http://www.iupac.org/publications/pac/2006/pdf/7811x2051.pdf
</translate> <languages />