# HCl dissolves

## Homework Statement

HCl gas dissolves in water consisting of hydrochloric acid, or hydrochloric acid. HCl dissociates
fully ions as follows: HCl → H+ + Cl-.

## Homework Equations

a) Calculate the pH of the solution, which is made ​​by dissolving 1.6 grams of HCl in 0.40 liters of water 298 K temperature.
b) How many ml it takes 0.050 mol/l NaOH solution, when it titraat 30 ml of 0.10 mol/l HCl solution?

## The Attempt at a Solution

a)
molar cencentration of H3O+ = n/V
n= 0.0438 mol
C= n/V = 0.0438/0.4 = 0.11 mol/l

PH = -log C of H3O+
PH = -log 0.11
PH = 0.96 (approximately)

b)
HCl with NaOH
Ca*Va = Cb*Vb -------------- we search V of NaOH
Vb = (Ca*Va)/Cb
Vb = (0.10*0.03)/0.050
Vb = 0.06 L
that's 60ml

Borek
Mentor
Looks OK.

HCl with NaOH
Ca*Va = Cb*Vb

Beware - you are omitting stoichiometric coefficients. They equal 1 in this case, so the equation holds, but it doesn't hold automatically for every titration.

Looks OK.

Beware - you are omitting stoichiometric coefficients. They equal 1 in this case, so the equation holds, but it doesn't hold automatically for every titration.

Thank you Borek
but how would it be if we had 2HCl and 1 NaOH
2 Ca*Va = Cb*Vb ?
also i wonder why they gave us the 298K

Borek
Mentor