Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Eyad Group Title

NOTE :THIS IS NOT A QUESTION,THIS IS A TUTORIAL. PH value & PoH value ==============

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. Eyad Group Title
    Best Response
    You've already chosen the best response.
    Medals 10

    PH Value : __________ *First of all ,what Ph Value mean ?? ===> pH is a measure of the hydrogen ion concentration, [H+] . *what is the formula which used to calculate the pH value ?? ===> pH is calculated using the following formula: pH = -log10[H+] . *_* Here is some examples about PH value and how to find it : ============================================================== Example 1: ___________ Find the pH of a 0.2mol L^-1 (0.2M) solution of HCl . Ans: 1-Write the balanced equation for the dissociation of the acid HCl -----> H+(aq) + Cl-(aq) 2- Use the equation to find the [H+]: 0.2 mol L- HCl produces 0.2 mol L-1 H+ since HCl is a strong acid that fully dissociates 3- Calculate pH: pH = -log10[H+] pH = -log10[0.2] = 0.7 Example 2: __________ Find the pH of a 0.2 mol L^-1 (0.2M) solution of H2SO4 . Ans: 1-Write the balanced equation for the dissociation of the acid H2SO4 -----> 2H+(aq) + SO42-(aq) 2- Use the equation to find the [H+]: 0.2 mol L-1 H2SO4 produces 2 x 0.2 = 0.4 mol L^-1 H+ since H2SO4 is a strong acid that fully dissociates 3- Calculate pH: pH = -log10[H+] pH = -log10[0.4] = 0.4 ****-A Tip: Hydrogen ion concentration, [H+], can be calculated using the following formula: [H+] = 10-pH . Example 3: ____________ *Find the [H+] of a nitric acid solution with a pH of 3.0 . Ans: pH= 3.0 [H+] = 10-pH [H+] = 10-3.0 = 0.001mol L^-1 You can check this answer by using the calculated value [H+] in the equation for pH to make sure you arrive at the original pH pH = -log10[H+] pH = -log10[0.001] = 3 We get the same value for pH using the calculated value for [H+], so the calculated value for [H+] is correct. ______________________________________________________________________________________________________________________________ Now Lets Move To POH Value: =========================== *-First of all ,What is POH value ? ====>pOH is a measure of the hydroxide ion concentration, [OH-]. *-what is the formula which used to calculate the poH value ?? ===>pOH is calculated using the following formula: pOH = -log10[OH-]. Now here is some Examples: =_=_=_=_==_=_=_=_==_=_=_=_= Example 1: _________ Find the pOH of a 0.1mol L^-1 (0.1M) solution of NaOH . Ans: 1-Write the balanced equation for the dissociation of the alkali NaOH -----> OH-(aq) + Na+(aq) 2- Use the equation to find the [OH-]: 0.1 mol L-1 NaOH produces 0.1 mol L^-1 OH- since NaOH is a strong alkali that fully dissociates 3- Calculate pOH: pOH = -log10[OH-] pOH = -log10[0.1] = 1 Example 2: __________ Find the pOH of a 0.1mol L^-1 (0.1M) solution of Ba(OH)2 . Ans: 1-Write the balanced equation for the dissociation of the alkali: Ba(OH)2 -----> 2OH-(aq) + Ba2+(aq) 2- Use the equation to find the [OH-]: 0.1mol L^-1 Ba(OH)2 produces 2 x 0.1 = 0.2 mol L^-1 OH- since Ba(OH)2 is a strong alkali that fully dissociates 3- Calculate pOH: pOH = -log10[OH-] pOH = -log10[0.2] = 0.7 *_* A TIP : Hydroxide ion concentration, [OH-], can be calculated using the following formula: [OH-] = 10-pOH . Example 3: __________ Find the [OH-] of a sodium hydroxide solution with a pOH of 1 pOH = 1 [OH-] = 10-pOH [OH-] = 10-1 = 0.1 mol L^-1 Ans: ==== pOH = 1 [OH-] = 10-pOH [OH-] = 10-1 = 0.1 mol L^-1 You can check this answer by using the calculated value [OH-] in the equation for pOH to make sure you arrive at the original pOH pOH = -log10[OH-]. ===================================================================================== If U have any questions ,please let me Know :)

    • 2 years ago
  2. Kryten Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    nicely done really! now just save yourself link to this "question" as i did so you can share leater upon question :D (and just from begining pH is measurement of activity (a) of H+ (H3O+) ions because pH doesnt have unit and you cant log unit... but great work nevertheless)

    • 2 years ago
  3. Eyad Group Title
    Best Response
    You've already chosen the best response.
    Medals 10

    Ty alot @Kryten . :)

    • 2 years ago
  4. UnkleRhaukus Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    this tutorial is very good. can i ask what the ranges (in practice and theoretical) for pH/pOH are

    • 2 years ago
  5. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Nice!

    • 2 years ago
  6. Eyad Group Title
    Best Response
    You've already chosen the best response.
    Medals 10

    @zepp :Ty :)

    • 2 years ago
  7. Kryten Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @UnkleRhaukus ranges for pH and pOH practicaly can go a lot further than 0-14, you have super acids which have pH of about -30 and bases with pH about 20. my sudgestion for you is to type super acid in google cause momentarily i dont have time to explain it... :) (hope you are not mad)

    • 2 years ago
  8. Sean_Le_Van Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    dayum. this kid is smart ;P

    • one year ago
    • Attachments:

See more questions >>>

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.