Hi,
I've watched a tutor solve a simple dilution solutions problem on video.
There's a calculation in that problem I wish you could clarify for me.
It goes like this:
Approximately what volume of water is needed to dilute 25.0 mL of 18.0 M sulfuric acid to 3.0 M ?
M * L = M * L
(18.0 M)(25.0 mL) = (3.0 M)(V)
vol = 150 mL of solution.
I calculate the volume here to be 4.17 mL. It's a little tricky. Could you please explain.
Thank You.
Have a Great Night.
try finding the Moles/liter first. convert the 25.0mL to Moles/L. See what cha come up with.
I have an easier way to understand.
you want 18M to 3M? that is a dilution of 6 times. So you want 1 part original, 5 parts water.
so, what is one part: in this case it is given: 25ml
so what is five parts: 125 ml.
to give a new total volume of acid at 3M of 150ml.
Try my method on these.
What if you wanted to use 18M acid to make 500ml of acid at 2.2M?
dilution factor 18/2.2 or 8.1818times
one part original, 7.1818 water
well, what is one part? 500ml/8.1818= 61.11ml.
what is 7.1818 parts: 61.11*7.1818=(500 / 8.1818) * 7.1818 = 438.888753
so, take 438.89 ml water, add 61.11 ml of the original acid (always add acid to water). and you have it.
I don't know how you came up with 4.17 mL. That may be the tricky part.
Hello! I'd be happy to explain the dilution calculation to you.
In this problem, you are given the initial concentration of sulfuric acid (18.0 M) and the desired final concentration (3.0 M). You are also given the initial volume (25.0 mL) and you need to find the volume of water needed to dilute the solution.
To solve this, you can use the formula: (initial concentration)(initial volume) = (final concentration)(final volume)
Let's break it down step by step:
Step 1: Write down the given information:
Initial concentration (Ci) = 18.0 M
Initial volume (Vi) = 25.0 mL
Final concentration (Cf) = 3.0 M
Step 2: Set up the equation using the formula mentioned above and plug in the values:
(Ci)(Vi) = (Cf)(Vf)
(18.0 M)(25.0 mL) = (3.0 M)(Vf)
Step 3: Solve for Vf (final volume):
Vf = (18.0 M)(25.0 mL) / 3.0 M
Vf = 450 mL / 3.0
Vf = 150 mL of solution
So, according to the dilution calculation, you would need to add approximately 150 mL of water to 25.0 mL of 18.0 M sulfuric acid to obtain a 3.0 M solution.
It seems that you calculated the volume to be 4.17 mL instead of 150 mL. It's possible that there might have been a mistake in your calculations, or perhaps you used a different formula.
I hope this explanation helps clarify the dilution calculation for you. If you have any more questions, feel free to ask! Have a great day!