select the correct answer from each drop - down menu. to prepare a 2 m solution of potassium nitrate (kno₃)…
select the correct answer from each drop - down menu. to prepare a 2 m solution of potassium nitrate (kno₃), which quantities must be measured? the mass of the and the volume of the must be measured. reset next
Answer
Explanation:
Step1: Recall molarity formula
Molarity ($M$) = $\frac{n}{V}$, where $n$ is the number of moles of solute and $V$ is the volume of the solution in liters. Also, $n=\frac{m}{M_m}$, where $m$ is the mass of the solute and $M_m$ is the molar - mass of the solute.
Step2: Determine what to measure
To prepare a solution of a given molarity, we need to know the number of moles of the solute. Since $n = \frac{m}{M_m}$, we need to measure the mass ($m$) of the solute (potassium nitrate, $KNO_3$). And we also need to measure the volume ($V$) of the solution to get the desired molarity.
Answer:
The mass of the potassium nitrate ($KNO_3$) and the volume of the solution must be measured.