The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Find amount of NaCl

A...


Posted from TSR Mobile
(edited 9 years ago)
Reply 1
Avatar for Pigster
Pigster
20
I wouldn't use simultaneous equations, just usual algebra will do.

n(AgCl) = n(Cl-) = n(Na+) + n(K+) = n(mixture)
Ar(Na+/K+ mixture) = 2.30 / n(mixture)
Let x = proportion of K, then 39x + 23(1-x) = Ar(mixture)
39x-23x = Ar-23
Solve.
(edited 9 years ago)
Reply 2
Avatar for genson
genson
OP
17
Original post by Pigster
I wouldn't use simultaneous equations, just usual algebra will do.

n(AgCl) = n(Cl-) = n(Na+) + n(K+) = n(mixture)
Ar(Na+/K+ mixture) = 2.30 / n(mixture)
Let x = proportion of K, then 39x + 23(1-x) = Ar(mixture)
39x-23x = Ar-23
Solve.


Yeah, I wouldn't use simultaneous equations either. It's the reason why I'm finding it so difficult but i have to otherwise I won't pass this assignment. It's really stupid.


Posted from TSR Mobile
Reply 3
Avatar for Pigster
Pigster
20
Just write, "I don't need to use simultaneous equations, so I refuse to use them. I've answered your question and got the correct answer, now give me all of the marks. No exam board worth sitting tells you how to answer a question, so why should you?"

But, just make sure you do indeed get the right answer.
Reply 4
Avatar for genson
genson
OP
17
Original post by Pigster
Just write, "I don't need to use simultaneous equations, so I refuse to use them. I've answered your question and got the correct answer, now give me all of the marks. No exam board worth sitting tells you how to answer a question, so why should you?"

But, just make sure you do indeed get the right answer.


The thing is, I'm doing a BTEC and the criteria to achieve the distinction in this particular assignment is that you have to use simultaneous equations to solve the problem given. I've asked my teacher repeatedly if you really do need to use simultaneous equations even if you get everything correct and he's very adamant you do. I might just try speaking to him again.


Posted from TSR Mobile
Reply 5
Avatar for genson
genson
OP
17
Original post by goodwinning





Posted from TSR Mobile

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you