pH of 1 means [H+] of 10^-1 = 0.1M
how do yk its 30ml added tho (not looking at answer)pH of 1 means [H+] of 10^-1 = 0.1M
Hence you need a final number of HCL moles in XS to produce that 0.1M concentration
When v added is 30mL you have a total v of 55mL, and you're adding 0.055mol HCl against 0.025mol NaOH
Hence 0.03mol H+ in excess and then solve accordingly
So the general stuff: HCL is monoprotic and has the same concentration as the base in this case right. So you need 25 ml of HCl to make a neutral solution.
the amount the concentration will be reduced beyond it is pretty negligible, you only need about 0.5mL more to account for it as @STBAccuracy shower. Imo the answer should really be D though since C doesn’t actually reach the pH required, D is the only one which exceeds itSo the general stuff: HCL is monoprotic and has the same concentration as the base in this case right. So you need 25 ml of HCl to make a neutral solution.
Now you want the final concentration to be 0.1M and the volume the current neutral solution is 50ml or 0.05 L
so u find the moles of hcl needed to get this concentration: n = c.v = 0.1x0.05 = 0.005 mol
then find the volume of hcl needed to produce this many moles:
v = n/c = 0.005/1 = 0.005L = 5ml
so u add to get 30 ml in total
(Someone confirm but idk why this method works like to me it doesn't make sense bc ur adding aqueous hcl so i dont know how my first n = vc thing works to get the moles required to make the concentration within 50ml its a bit confusing @carrotsss help)
I would just check between b c d after the first step since its mcq ....