multiple choice help (1 Viewer)

[esraa]

Heyy this is a past question.. i calculated the pH of NaCl as 4 but it asks for the resultant solution?? answer is B.

20 mL of 0.08 mol L–1 HCl is mixed with 30 mL of 0.05 mol L–1 NaOH.
What is the pH of the resultant solution?

(A)1.1
(B)2.7
(C)4.0
(D)7.0

 

[niggas10]

u suck, thats been asked atleast 4times on this site before.

But im not going to help u anyway

 

[esraa]

my badd a 5th time is always good .. im not even asking for ur help anyway

 

[HyperComplexxx]

n(HCl) = 1.6x10^-3 moles
n(NaOH) = 1.5x10^-3 moles
HCl and NaOH react but n(HCl) is in excess so there is 1x10^-4 moles of HCl left
Now calculate pH,
C = n/v
C(H+) = 1x10^-4 / 0.05 <---- volume has increased (20mL + 30mL = 0.05L)
C(H+) = 2x10^-3 mol/L
pH = -log2x10^-3
= 2.7

Lol i forgot how to use LaTeX

 

[esraa]

Thankyouuu!