# How many moles of water are present in 90g of water?

$\begin{array}{1 1}(a)\;1\;mole\\(b)\;18\;mole\\(c)\;5\;mole\\(d)\;10\;mole\end{array}$

Number of Moles $n = \large\frac{\text{Amount of water}}{\text{Molecular mass of water}}$
We know that the molecular mass of water $=18\;g\;mol^{-1}$
$\Rightarrow n = \large\frac{90\;g}{18\;g\;mol^{-1}}$$= 5\; mol$
answered Feb 12, 2014
edited Jul 16, 2014