Question

please help!!!
Which of the following situations could be represented with the given system of equations?

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A.
Eunice needs to combine solutions of 0.1M HCl and 0.4M HCl to produce 5L of 0.6M hydrochloric acid (HCl).
B.
Eunice needs to combine solutions of 0.1M HCl and 0.6M HCl to produce 5L of 0.4M hydrochloric acid (HCl).
C.
Eunice needs to combine solutions of 0.4M HCl and 0.6M HCl to produce 5L of 0.1M hydrochloric acid (HCl).
D.
Eunice needs to combine solutions of 0.1M HCl and 0.6M HCl to produce 4L of 0.5M hydrochloric acid (HCl).

Answer 1

a concentration will be the same no matter how much of the fluid you got. if you have more of the fluid, you get more HCI and also more acid components.

so the first equation will tell you the concentration given the two concentration levels 0.1M and 0.6M, when you have [x] and [y] of it in the mix.
It also was set up and prepared to find the required balance for a 0.4M solution.

this gives you concentration per L of HCI:
total concentration = (x*0.1 + y*0.6) / x+y

they have set it to be 0.4:
target concentration 0.4M = (x*0.1+y*0.6) / x+y

it is also stated a target of 5L is wished, so the total x+y will be 5L:
0.4M = (x*0.1 + y*0.6)/5

we want to solve for x and y, so:
0.4M x 5 = x*0.1 + y*0.6

Answer 2

so far we have:
x*0.1 + y*0.6
0.4 = -------------
5


there's still a problem though: we have put 5 in the place of x+y.

but nowhere do we have the information that this was supposed
to be x+y, which is a requirement.

if there's just a 5, we could dump large amounts of x,
and the denominator wouldn't change, which is not allowed.
(in reality, it would be necessary to adjust the denominator!!)
(just because there are more acid components that doesn't
increase acidity if water components come with it.)

we need to have that x+y=5. then, the equation really works
and will get us 5L of fluid that has 0.4M.

5 in the denominator, if x+y = 5.
and we want total to be 5L, so the contributions from the acids x+y must be=5L.

Answer 3

thank u

Answer 4

whats the answer