Molar fraction

The molar fraction of a component $i$ in a mixture is defined as:

$X_{i}={\frac {n_{i}}{\sum _{j=1}^{N}n_{j}}}$

where $n_{i}$ is the number of moles of component Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle i} .