HCl Dissolving in Water: Calculating pH and Titration with NaOH

[chawki]

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]

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.

 

[chawki]

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]

but how would it be if we had 2HCl and 1 NaOH
2 Ca*Va = Cb*Vb ?

That's not how they react. See

http://www.titrations.info/titration-calculation

also i wonder why they gave us the 298K

My guess is they gave it to make you wonder...

 

[DeeNos]

I would like to provide some feedback on your attempt at solving these problems. Your calculations for the pH and titration are correct, but it would be beneficial to include more explanation and context for these calculations. For example, you could explain the significance of calculating pH and how it relates to the dissociation of HCl in water. Additionally, you could explain the purpose of titration and how it is used to determine the concentration of a solution. Including these details would not only make your response more informative, but also help the reader understand the concepts better.