4. You use a volumetric pipette to take 10 mL of a stock
solution of KMnO and add water to make a more dilute
solution in a 100 mL volumetric flask. Is there more
potassium permanganate in the volumetric pipette or
the 100 mL of solution? Justify your answer
You draw 10 mL of the KMnO4 solution into the pipette and transfer all of it to a 100 mL volumetric flask. Now the flask contains what was in the pipette, no more, no less. The concentration in the flask, because it is diluted, is smaller by a factor or 10 (100 mL/10 mL) but the amount of KMnO4 is the same.
Well, let me break it down for you. When you use a volumetric pipette to draw 10 mL of a stock solution, you're transferring a specific volume from the stock solution. So, obviously, the volumetric pipette contains more potassium permanganate than the 100 mL solution. It's like comparing a tiny clown car to a clown bus - the pipette is smaller, but it's packed with a higher concentration of KMnO. So, the pipette wins this round in the battle of potassium permanganate!
In this scenario, we are using a volumetric pipette to transfer 10 mL of a stock solution of KMnO4 into a 100 mL volumetric flask. We then add water to the flask to make a more dilute solution.
To determine if there is more potassium permanganate (KMnO4) in the volumetric pipette or the 100 mL of solution, we need to consider the concentrations.
The stock solution is more concentrated than the diluted solution in the flask. Therefore, the 10 mL of stock solution added to the 100 mL volumetric flask contains more KMnO4 than the resulting diluted solution.
The volumetric pipette holds exactly 10 mL of the stock solution, so all 10 mL transferred from the pipette to the flask contains KMnO4. On the other hand, the 100 mL of solution in the flask contains only a smaller proportion of the 10 mL of KMnO4, as it has been diluted with additional water.
Therefore, the volumetric pipette contains more potassium permanganate (KMnO4) than the 100 mL of solution in the volumetric flask.
To determine if there is more potassium permanganate (KMnO4) in the volumetric pipette or the 100 mL solution, we need to consider the dilution process.
First, let's understand the purpose of a volumetric pipette and a volumetric flask. A volumetric pipette is a precision measuring instrument used to transfer a specific volume of liquid (in this case, the stock solution) accurately. On the other hand, a volumetric flask is used to prepare a specific volume of a solution by adding a solute (in this case, water) to achieve the desired concentration.
In the given scenario, you used a volumetric pipette to transfer 10 mL of the stock solution into a 100 mL volumetric flask. The remaining volume in the flask was then filled with water.
To determine which has more KMnO4, we need to compare the amount of KMnO4 in 10 mL of the stock solution and the resulting solution in the 100 mL volumetric flask.
First, let's assume the initial concentration of the stock solution was C1 (in terms of moles per liter) and the resulting solution in the flask has a concentration of C2.
The concentration in the volumetric pipette can be calculated as follows:
Amount of KMnO4 in pipette = C1 x V1
(in this case, V1 is 10 mL)
The concentration in the volumetric flask can be calculated as follows:
Amount of KMnO4 in flask = C2 x V2
(in this case, V2 is the final volume of the solution in the flask, which is 100 mL)
Since we diluted the stock solution by adding water, the total amount of KMnO4 in both the pipette and the flask should remain the same. Therefore, we can equate the two quantities:
C1 x V1 = C2 x V2
Since we already know V1 and V2, we need to compare the concentrations C1 and C2.
In this case, since we diluted the stock solution by adding water, the concentration of KMnO4 in the volumetric flask (C2) would be lower than that in the volumetric pipette (C1).
So, the volumetric pipette contains a higher concentration of KMnO4 compared to the resulting solution in the 100 mL volumetric flask.