The Student Room Group

Equilibrium question

Screenshot 2017-01-22 14.02.12.png

Is it:

volume x density = mass
moles = mass/mr ?
(edited 7 years ago)
Reply 1
Bump
Reply 2
You will find n(NaOH), some of that reacted with the HCl, the rest with the Pr-1-OH.
Reply 3
Original post by Pigster
You will find n(NaOH), some of that reacted with the HCl, the rest with the Pr-1-OH.


? doesnt NaOH react with the hcl, propan-1-ol AND propanoic acid?


Im cant remember why but id written down:

volume x density = mass
moles = mass/mr
Reply 4
Original post by kiiten
? doesnt NaOH react with the hcl, propan-1-ol AND propanoic acid?


Whooops, typo. It doesn't react with the alcohol, it will react with the HCl and th PrOOH.

Since you're given volumes, you need to convert volume into mass to allow you to then convert into amounts.
Original post by kiiten
Screenshot 2017-01-22 14.02.12.png

Is it:

volume x density = mass
moles = mass/mr ?


Yes.
Reply 6
Original post by Pigster
Whooops, typo. It doesn't react with the alcohol, it will react with the HCl and th PrOOH.

Since you're given volumes, you need to convert volume into mass to allow you to then convert into amounts.


How do you know only hcl and propanoic acid reacts?
Original post by kiiten
How do you know only hcl and propanoic acid reacts?


Sodium hydroxide is a base and reacts with acids.

But that's not what your question asked originally.
Reply 8
Original post by charco
Sodium hydroxide is a base and reacts with acids.

But that's not what your question asked originally.


Ah yeah of course so:

volume of original method - volume of reacted mixture = volume of propanol?

Then find mass (density x volume) and moles (mass/ mr)
Original post by kiiten
Ah yeah of course so:

volume of original method - volume of reacted mixture = volume of propanol?

Then find mass (density x volume) and moles (mass/ mr)

Actually they just want the moles of propanol from the start. So before you added it to the flaks. It's simply propanol volume × density to find the mass of propanol. Then mass/Mr.
PS Fellow army here 👋 :smile:
Reply 10
Original post by Selgomez11
Actually they just want the moles of propanol from the start. So before you added it to the flaks. It's simply propanol volume × density to find the mass of propanol. Then mass/Mr.
PS Fellow army here 👋 :smile:


Hey :smile:

Ughh so they included the other info for no reason?
Original post by kiiten
Hey :smile:

Ughh so they included the other info for no reason?


Read the question carefully.

You are probably going to use the other data later on in the question.
Reply 12
Original post by charco
Read the question carefully.

You are probably going to use the other data later on in the question.


Later on as in the questions after this e.g. part i)

For this question is it just mass = volume x density then mass/mr ?

Posted from TSR Mobile
Original post by kiiten
Later on as in the questions after this e.g. part i)

For this question is it just mass = volume x density then mass/mr ?

Posted from TSR Mobile


yes

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