Molar fraction

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

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 X_i = \frac{n_i}{\sum_{j=1}^{N} n_j} }