# Question #f1733

May 26, 2015

You have 0.0180 moles of hydrobromic acid in your sample.

Molarity is defined as moles of solute, in yourcase hydrobromic acid, divided by liters of solution.

This means that you can use the solution's molarity and its volume to determine how many moles of the solute are present.

$C = \frac{n}{V} \implies n = C \cdot V$

${n}_{H B r} = 0.200 \text{mol"/cancel("L") * 90.0 * 10^(-3)cancel("L") = "0.0180 moles}$ $H B r$

Notice that you need to convert the volume from mL to liters, since molarity is always given as moles per liter.