Question #f0b84

Oct 18, 2016

Molarity of a solution is the proportion between number of mols of the solute and volume of solution: $c = \frac{n}{V}$. From mass of the solute, you can calculate the number of mols and then the volume.

Explanation:

To calculate the volume of solution containing a certain amount of solute, if we know the molarity of the solution we can use the following scheme:

In this case, as they give us the mass of solute we need molecular mass to know how many moles there in that amount of solute.

The molecular mass of $C u N {O}_{3}$ is:

${M}_{r} \left(C u N {O}_{3}\right) = {A}_{r} \left(C u\right) + {A}_{r} \left(N\right) + 3 \cdot {A}_{r} \left(O\right) = 63.5 + 14 + 3 \cdot 16 = 125.5 g \cdot m o {l}^{- 1}$

Then, we have:

$2.86 g \left(H N {O}_{3}\right) \times \frac{1 m o l \left(H N {O}_{3}\right)}{125.5 g \cdot m o {l}^{- 1}} \times \frac{1 L s o l u t i o n}{0.830 m o l \left(H N {O}_{3}\right)} = 0.0275 L$