You are a work study student in our chemistry department. Amy, your supervisor has just asked you to prepare 250ml of 0.500M NH3 solution for tomorrow's undergraduate experiment. The Stock Solutions cabinet is under the Stockroom Explorer. You will find find a 2.50 liter bottle containing 14.8M NH3. Please prepare a flask containing 250ml of a 0.500M solution. To ensure proper credit, please write your calculations in the space given below.
The dilution formula is mLa x Ma = mLb x Mb
Y mL x 14.8 M = 250 mL x 0.500 M
Solve for Y liters. I get about 8.44 mL.
So transfer 8.44 mL of the stock solution to a 250 mL volumetric flask, add enough distilled water to make to the mark of the volumetric flask, stopper, mix thoroughly, label, done.
Well, that sounds like quite the task! Let's see if we can bring some humor into these calculations:
To prepare a 0.500M NH3 solution, we can use the formula:
M1 x V1 = M2 x V2
Where:
M1 = initial concentration (14.8M)
V1 = initial volume (unknown, we'll solve for it)
M2 = final concentration (0.500M)
V2 = final volume (250ml)
Now, let's solve for V1:
14.8M x V1 = 0.500M x 250ml
V1 = (0.500M x 250ml) / 14.8M
V1 = 8.45ml
So, to prepare a 250ml of 0.500M NH3 solution, you will need to dilute 8.45ml of the 14.8M NH3 solution with enough solvent (probably water) to reach a final volume of 250ml.
Always remember, chemistry can be a total solution to all your problems! Just don't mix up the chemicals, that could create an explosive situation!
To prepare 250 ml of a 0.500M NH3 solution using a 14.8M NH3 stock solution, we can use the following equation:
C1V1 = C2V2
Where:
C1 = Concentration of the stock solution
V1 = Volume of the stock solution
C2 = Desired concentration of the final solution
V2 = Desired volume of the final solution
Given:
C1 = 14.8M
V1 = 2.50L (convert to ml by multiplying by 1000: 2.50L * 1000ml/L = 2500ml)
C2 = 0.500M
V2 = 250ml
Let's substitute these values into the equation and solve for V1:
(14.8M) * V1 = (0.500M) * (250ml)
14.8V1 = 0.500 * 250
14.8V1 = 125
V1 = 125 / 14.8
V1 ≈ 8.45ml (rounded to two decimal places)
So, to prepare 250ml of a 0.500M NH3 solution, you will need to measure 8.45ml of the 14.8M NH3 stock solution and add it to a flask. Then, add enough solvent (e.g., water) to the flask to bring the total volume up to 250ml.
To prepare a 250 ml of a 0.500 M NH3 solution from the given stock solution, you need to calculate the volume of the stock solution required and then dilute it to the desired concentration.
Here's how you can calculate it:
Step 1: Determine the moles of NH3 required.
The formula to calculate moles is:
moles = volume (in liters) * concentration (in moles per liter)
moles NH3 = volume of solution * concentration of NH3
= 0.250 L * 0.500 mol/L
= 0.125 moles NH3
Step 2: Calculate the volume of the stock solution required.
The formula to calculate volume is:
volume of stock solution = moles of solute / concentration of stock solution
volume of stock solution = moles NH3 / concentration of stock solution
= 0.125 moles / 14.8 M
= 0.008445 liters
= 8.445 ml
Step 3: Dilute the stock solution.
To dilute the stock solution, add deionized water to the calculated volume of the stock solution obtained in step 2 (8.445 ml) so that the final volume is 250 ml.
The volume of water required is:
volume of water = final volume - volume of stock solution
= 250 ml - 8.445 ml
= 241.555 ml
Therefore, you need to take 8.445 ml of the 14.8 M NH3 stock solution and dilute it with 241.555 ml of deionized water to obtain 250 ml of a 0.500 M NH3 solution.
Note: It is important to accurately measure the volumes and handle the chemicals safely when preparing the solution. Make sure to follow proper lab procedures and safety guidelines.