Question

kai wants to create 0.250 l of 0.200 m potassium permanganate solution. the molar mass of kmno₄ is 158.04 g/mol. what mass of potassium permanganate does he need to use to create the solution? ? g potassium permanganate

Explanation:

Step1: Recall the formula for molarity

Molarity ($M$) is defined as moles of solute ($n$) divided by volume of solution in liters ($V$), so $M=\frac{n}{V}$. We can rearrange this to find moles: $n = M\times V$.
Given $M = 0.200\ M$ (which is $\frac{mol}{L}$) and $V = 0.250\ L$, we substitute these values:
$n=0.200\ \frac{mol}{L}\times0.250\ L = 0.0500\ mol$

Step2: Use molar mass to find mass

The formula relating moles, molar mass ($MM$), and mass ($m$) is $n=\frac{m}{MM}$, so we can rearrange to $m = n\times MM$.
Given $MM = 158.04\ \frac{g}{mol}$ and $n = 0.0500\ mol$, we substitute:
$m=0.0500\ mol\times158.04\ \frac{g}{mol}=7.902\ g$ (we can round to appropriate significant figures, here it's 7.90 g or 7.902 g as per calculation)

Answer:

7.90 (or 7.902)