Mass of reactants in a chemical equation (3590)

, por F_y_Q

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How many grams of \ce{O_2} are needed to react with 120 g of \ce{NO} to obtain \ce{NO_2}?

P.-S.

The chemical equation is:

\color[RGB]{2,112,20}{\textbf{\ce{2NO + O2 -> 2NO2}}}

The molecular mass of \ce{NO} is:

M_{\ce{NO}} = (14\cdot 1 + 16\cdot 1) = \color[RGB]{0,112,192}{\bm{30\ g\cdot mol^{-1}}}

Oxygen has a molecular mass of:

M_{\ce{O2}} = (16\cdot 2) = \color[RGB]{0,112,192}{\bm{32\ g\cdot mol^{-1}}}

According to the chemical equation 60 g of \ce{NO} will require 32 g of \ce{O_2} to complete the reaction. Let’s perform a mathematical proportion to determine the required mass of oxygen:

120\ \cancel{\ce{g\ NO}}\cdot \frac{32\ \ce{g\ O2}}{60\ \cancel{\ce{g\ NO}}} = \fbox{\color[RGB]{192,0,0}{\textbf{64 g \ce{O2}}}}