Question

A chemist prepares a solution of potassium permanganate (KMnO4) by measuring out 25.7 micro moles of potassium permanganate into a volumetric flask and filling the flask to the mark with water.Calculate the concentration in mol/L of the chemist's potassium permanganate solution. Round your answer to 3significant digits

Answer 1

what size is the volumetric flask?

Answer 2

450 mL

Answer 3

sorry lol

Answer 4

please help jfraser

Answer 5

the units of concentration are \[M = \frac{mol \space solute}{L \space solution}\] You have enough information already to plug into the fraction and solve

Answer 6

ok so out 25.7/450 ?

Answer 7

im confused about where to place things

Answer 8

i mean so put

Answer 9

please help im confused

Answer 10

the numbers are the least important thing to use, when you have to solve chemistry problems. Read the problem, and look at what the units say.

25.7 MICRO-moles in 450 mL

but the units of molarity have to be MOLES per LITER. You have to pay attention to the prefixes that units sometimes come with.

Answer 11

MICRO means 1 million times smaller, so 25.7 micromoles is 0.0000257 moles of KMnO4

MILLI means 1 thousand times smaller, so 450mL is 0.450L

Those are the numbers that have to be plugged in, and where they go will be determined by the UNITS

\[M = \frac{mol \space solute}{L \space solution} = \frac{0.0000257mol \space KMnO_4}{0.450L}\]

Answer 12

so first convert the micro moles into moles

Answer 13

and since the are asking for m/L places the new find moles over the size of the flask

Answer 14

yes

Answer 15

be careful using "m" for moles, since "m" is usually reserved for meters. Most everyone uses "mol" for moles, that way there's less confusion

Answer 16

omg thank you so so much u saved me!

Answer 17

im now your fan!

Answer 18

anytime