Question

Num recipiente estão contidas 1,20 . 10²³ moléculas de H2O.
Calcular a massa , em gramas, dessa quantidade de água.

Answer 1

$\large\boxed{\begin{array}{l}\rm 18\,g\longrightarrow 6\cdot10^{23}\,mol\acute eculas\\\rm x\,g\longrightarrow 1,2\cdot10^{23}\,mol\acute eculas\\\rm 6\cdot10^{23}x=1,2\cdot10^{23}\cdot18\\\rm x=\dfrac{1,2\cdot\diagup\!\!\!\!\!\!\!10^{23}\cdot\diagdown\!\!\!\!\!\!\!18^3}{\diagdown\!\!\!\!6\cdot\diagup\!\!\!\!\!\!\!10^{23}}\\\\\rm x=1,2\cdot3\\\rm x=3,6\,g\,de\,H_2O\end{array}}$