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

Answer from: 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

Answer from: 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

Answer from: Quest

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates

Answer from: Quest

The answer is d- principle of faunal succession.

Another question on Chemistry

Chemistry, 21.06.2019 19:00

Which term best describes the form sound takes as it travels away from a drum (a- gas)(b-music) ( c-waves) (d-particles

Answers: 3

Answer

Chemistry, 22.06.2019 13:00

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?

Answers: 1

Answer

Chemistry, 23.06.2019 00:30

Which of the following best describes technology a. something created for only scientists to use b.the method of thinking that scientists use. c.the application of engineering to create useful products. c. a scientific idea

Answers: 1

Answer

Chemistry, 23.06.2019 01:30

How many atoms are in 2 moles of phosphorus

Answers: 1

Answer

You know the right answer?

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

Questions