6/14/2018 1159 PM 60.2/100 Gradeboo -Print Calculator Periodic Table Question 45 of 55 Sapling Learning Map At 25 ?, how many dissociated OH ions are there in 1 267 mL of an aqueous solution whose pH is 2.08? Number ions O Previous Give Up & View Solution Check Answer Next x to search ?
Solution
use:
pH = -log [H+]
2.08 = -log [H+]
[H+] = 8.318*10^-3 M
use:
[OH-] = Kw/[H+]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[OH-] = (1.0*10^-14)/[H+]
[OH-] = (1.0*10^-14)/(8.318*10^-3)
[OH-] = 1.202*10^-12 M
number of mol of OH- = [OH-] * volume in L
= 1.202*10^-12 M * 1.267 L
= 1.523*10^-12 mol
number of OH- = number of mol * Avogadro’s number
= 1.523*10^-12 mol * 6.022*10^23 ions/mol
= 9.17*10^11 ions
Answer: 9.17*10^11 ions
.
1. 6/14/2018 1159 PM 60.2/100 Gradeboo -Print Calculator Periodic Table Question 45 of 55
Sapling Learning Map At 25 ?, how many dissociated OH ions are there in 1 267 mL of an
aqueous solution whose pH is 2.08? Number ions O Previous Give Up & View Solution Check
Answer Next x to search ?
Solution
use:
pH = -log [H+]
2.08 = -log [H+]
[H+] = 8.318*10^-3 M
use:
[OH-] = Kw/[H+]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[OH-] = (1.0*10^-14)/[H+]
[OH-] = (1.0*10^-14)/(8.318*10^-3)
[OH-] = 1.202*10^-12 M
number of mol of OH- = [OH-] * volume in L
= 1.202*10^-12 M * 1.267 L
= 1.523*10^-12 mol
number of OH- = number of mol * Avogadro’s number
= 1.523*10^-12 mol * 6.022*10^23 ions/mol
![6/14/2018 1159 PM 60.2/100 Gradeboo -Print Calculator Periodic Table Question 45 of 55
Sapling Learning Map At 25 ?, how many dissociated OH ions are there in 1 267 mL of an
aqueous solution whose pH is 2.08? Number ions O Previous Give Up & View Solution Check
Answer Next x to search ?
Solution
use:
pH = -log [H+]
2.08 = -log [H+]
[H+] = 8.318*10^-3 M
use:
[OH-] = Kw/[H+]
Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC
[OH-] = (1.0*10^-14)/[H+]
[OH-] = (1.0*10^-14)/(8.318*10^-3)
[OH-] = 1.202*10^-12 M
number of mol of OH- = [OH-] * volume in L
= 1.202*10^-12 M * 1.267 L
= 1.523*10^-12 mol
number of OH- = number of mol * Avogadro’s number
= 1.523*10^-12 mol * 6.022*10^23 ions/mol](https://image.slidesharecdn.com/6-14-20181159pm60-2-100gradeboo-printcalculatorperiodictableq-230127024335-b44d54f4/85/6-14-2018-1159-PM-60-2-100-Gradeboo-Print-Calculator-Periodic-Table-Q-docx-1-320.jpg)
