Chemistry, 28.07.2019 07:00, elysabrina6697

Calculate the ph after 0.020 mol hcl is added to 1.00 l of each of the four solutions below.

Answers: 1

Show answers

Answers

answered: Jacques1b

The pH of the solutions after adding 0.02mol of HCl will be 1.7, 1.69, 1.7, and 6.4 respectively.

pH is used to measure the alkalinity and acidity of the solutions. pH 7 is neutral.

For solution A,

$\bold {Kb =\dfrac {[OH^-][HONH3+]}{[NH2OH]} }$

put the value and solve it for [OH]

$\bold {[OH^-] = 6.6x10^-^5 M }$

$\bold{ pOH = -log[OH]}\\\\\bold{ pOH = -log(6.6x10^-^5)}\\\\\bold {pOH = 4.18}}\\$

Since, pH = 14 - pOH

pH = 9.82

Since, $\bold{[H^+] = 0.02}$

$\bold {pH = -log (0.02)}\\\bold {pH = 1.7}$

For Solution B

$\bold {Ka [HONH_3Cl ]= 9.09x10^-7 }\\\\\bold {Ka = \dfrac { [H+][HONH2]} { [HONH3+]}}$

Since, $\bold { [H^+] = 6x10^-^4 }$

So, pH = $\bold {pH = -log (6x10^-4) = 3.22}$

The new pH will be

$\bold {pH = -log (6x10^-4+0.02)}\\\bold {pH = 1.69}$

$\bold{[H^+] = 0.02}\\\bold {pH = -log (0.02)}\\\bold {pH = 1.7}$

(D) Since, $\bold {HONH_2}$ and $\bold {HONH_3Cl}$ are at same concentration.

So, $\bold {pH = pKa}$

$\bold {Pka = -log Ka}\\\\\bold {pKa = -log 9.09x10^-7}\\\\\bold{ pKa = 6.04}\\\\\bold{ pH = 6.04}$

Therefore, The pH of the solutions after adding 0.02mol of HCl will be 1.7, 1.69, 1.7, and 6.4 respectively.

To know more about pH

link

answered: meiyrarodriguez

A) according to this reaction:
by using ICE table:
NH2OH(aq) + H2O(l) → HONH3+(aq) + OH-
initial 0.4 M 0 0
change -X +X +X
Equ (0.4-X) X X

when Kb = [OH-][HONH3+]/[NH2OH]
when we have Kb = 1.1x10^-8 so,
by substitution:
1.1x10^-8 = X^2/(0.4-X) by solving this equation for X

∴X = 6.6x10^-5 M
∴[OH] = 6.6x10^-5 M
when POH = - ㏒[OH]
∴POH = -㏒(6.6x10^-5)= 4.18
∴PH = 14 - POH = 14 - 4.18
= 9.82
when PH = -㏒[H+]
∴[H+] = 10^9.82 = 1.5x10^-10 M+0.02molHcl
= 0.02
∴ the new value of PH = -㏒(0.02)
∴PH = 1.7

B) according to this reaction:
by using ICE table:
HONH3+(aq) → H+(aq) + HONH2(aq)
intial 0.4 0 0
change -X +X +X
Equ (0.4-X) X X

when Ka HONH3Cl = 9.09x10^-7
and Ka = [H+][HONH2] / [HONH3+]

So by substitution and we can assume [HONH3+] = 0.4 as the value of Ka is so small so,
9.09x10^-7 = X^2 / 0.4 by solving for X
∴ X = 6 x 10 ^-4
∴[H+] = 6x10^-4
PH = -㏒[H+]
= -㏒ (6x10^-4) = 3.22
when [H+] = 6x10^-4 + 0.02 m HCl
∴new value of PH = -㏒(6x10^-4+0.02)
= 1.69
C) when we have pure H2O and PH of water = 7
So we can get [H+] when PH = -㏒[H+]
∴[H+] = 10^-7 + 0.02MHCl
= 0.02
∴new value of PH = -㏒0.02
PH = 1.7
d) when HONH2 & HONH3Cl have the same concentration and Hcl added to them so we can assume that PH=Pka
and when we have Ka for HONH3Cl = 9.09x10^-7
So we can get the Pka:

Pka = -㏒Ka
= -㏒9.09x10^-7
= 6.04
∴PH = 6.04
and because of the concentration of the buffer components, HONH2 & HONH3Cl have 0.4 M and the adding of HCl = 0.02 M So PH will remain very near to 6

answered: Guest

We can’t you if you only tell us that you have to show us what the answers are

answered: Guest

2.00 is the !

Other questions on the subject: Chemistry

Chemistry, 22.06.2019 00:00, kdior27

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.

Answers: 3

continue

Chemistry, 22.06.2019 03:30, tbeck225

If a solution is considered basic, then a) the hydroxide ion and hydronium ion concentrations are equal. b) the hydroxide ion concentration is less than the hydronium ion concentration. c) the hydronium ion concentration is greater than the hydroxide ion concentration. d) the hydroxide ion concentration is greater than the hydronium ion concentration.

Answers: 1

continue

Chemistry, 22.06.2019 05:00, hjamya17

In 1901, thomas edison invented the nickel-iron battery. the following reaction takes place in the battery. fe(s) + 2 nio(oh)(s) + 2 h2o(l) fe(oh)2(s) + 2 ni(oh)2(aq) how many mole of fe(oh)2, is produced when 5.35 mol fe and 7.65 mol nio(oh) react?

Answers: 1

continue

Chemistry, 22.06.2019 10:00, sdlesley66

Miner's coal distributors does not mine coal itself, nor does it even store or handle the coal. instead, miner's solicits orders for low sulfur coal from other firms, then purchases the required amount from suppliers and directs them to ship the coal to its customers. what is miner's

Answers: 1

continue

Do you know the correct answer?

Calculate the ph after 0.020 mol hcl is added to 1.00 l of each of the four solutions below....