Need help with titration calc question (1 Viewer)

[yonezwxu]

Hi, I’m a bit stuck on this question so if anyone could help me out I would appreciate it! When you are trying to find the concentration of the diluted vinegar, does it refer to the 25ml of vinegar in the conical flask or the 250ml of vinegar in the volumetric flask? Or does it not matter? I’m confused about what volume i should be putting into c=n/v to find the concentration of diluted vinegar. I’ve attached the question and my attempt for it below, but still not sure if I am correct or not

If anyone have a better method to use for solving these types of titration calculations then I’m open to learn
I was told by my teacher that you should draw a diagram for each question

Also does anyone know where to find useful titration question to practise as I’m a bit hesitant to jump straight to past papers bc I don’t feel that comfortable with titration calculation

 

[cheesynooby]

Hi, I’m a bit stuck on this question so if anyone could help me out I would appreciate it! When you are trying to find the concentration of the diluted vinegar, does it refer to the 25ml of vinegar in the conical flask or the 250ml of vinegar in the volumetric flask? Or does it not matter? I’m confused about what volume i should be putting into c=n/v to find the concentration of diluted vinegar. I’ve attached the question and my attempt for it below, but still not sure if I am correct or not

did u mean 100ml instead of 250ml? i don't see any mentions of 250ml in the question :0
the concentration should be the same regardless of whether you are calculating it for the 100ml solution or the 25ml aliquot because when you take a sample of the 100ml solution you aren't changing the concentration
so, the V value you use just depends on where you get the n value from (so what is the number of moles u calculated for?)
in this case, you calculated the number of moles of NaOH to neutralise the acetic acid in the 25ml solution (which would be 1:1, also it would probably be better if you justified this in your working to show why n(NaOH) = n(CH3COOH)) so you calculated the number of moles of acetic acid in the 25ml solution (so you should then use a V value of 25ml). if you wanted to use the 100ml for the V value, you should multiply the number of moles by 4 (since there would be 4x the number of moles in the 100ml solution than in the 25ml solution)

btw ur chemical formula for acetic acid kinda looks like CH3COON..

other than that your method seems fine!!

 

[yonezwxu]

did u mean 100ml instead of 250ml? i don't see any mentions of 250ml in the question :0
the concentration should be the same regardless of whether you are calculating it for the 100ml solution or the 25ml aliquot because when you take a sample of the 100ml solution you aren't changing the concentration
so, the V value you use just depends on where you get the n value from (so what is the number of moles u calculated for?)
in this case, you calculated the number of moles of NaOH to neutralise the acetic acid in the 25ml solution (which would be 1:1, also it would probably be better if you justified this in your working to show why n(NaOH) = n(CH3COOH)) so you calculated the number of moles of acetic acid in the 25ml solution (so you should then use a V value of 25ml). if you wanted to use the 100ml for the V value, you should multiply the number of moles by 4 (since there would be 4x the number of moles in the 100ml solution than in the 25ml solution)

btw ur chemical formula for acetic acid kinda looks like CH3COON..

other than that your method seems fine!!

omg yes i meant 100ml my bad im a bit tired today
so i should just use V as 25ml to find concentration and then go straight to the C1V1=C2V2 formula right? i think i understand this a bit better now thanks to u!
thanks for pointing out that my chemical formula for acetic acid kinda looks like CH3COON i didn't realise that oops