When an object kinetic energy changes what happens to the object??

Calculate the pH and fraction of dissociation ( α ) for each of the acetic acid ( CH 3 COOH , p K a = 4.756 ) solutions. A 0.002

marysya [2.9K]

Answer:

The degree of dissociation of acetic acid is 0.08448.

The pH of the solution is 3.72.

Explanation:

The $pK_a=4.756$

The value of the dissociation constant = $K_a$

$pK_a=-\log[K_a]$

$K_a=10^{-4.756}=1.754\times 10^{-5}$

Initial concentration of the acetic acid = [HAc] =c = 0.00225

Degree of dissociation = α

$HAc\rightleftharpoons H^++Ac^-$

Initially

c

At equilibrium ;

(c-cα) cα cα

The expression of dissociation constant is given as:

$K_a=\frac{[H^+][Ac^-]}{[HAc]}$

$1.754\times 10^{-5}=\frac{c\times \alpha \times c\times \alpha}{(c-c\alpha)}$

$1.754\times 10^{-5}=\frac{c\alpha ^2}{(1-\alpha)}$

$1.754\times 10^{-5}=\frac{0.00225 \alpha ^2}{(1-\alpha)}$

Solving for α:

α = 0.08448

The degree of dissociation of acetic acid is 0.08448.

$[H^+]=c\alpha = 0.00225M\times 0.08448=0.0001901 M$

The pH of the solution ;

$pH=-\log[H^+]$

$=-\log[0.0001901 M]=3.72$

3 0

3 years ago

A mixture of helium and nitrogen gases, in a 7.03 L flask at 17 °C, contains 0.738 grams of helium and 8.98 grams of nitrogen. T

Andrei [34K]

Answer:

The partial pressure of nitrogen in the flask is 1.08 atm and the total pressure in the flask is 1.70 atm.

Explanation:

We must use the Ideal Gas Law to solve this:

Pressure . volume = n . R . T

T = T° in K → T°C + 273

17°C + 273 = 290K

n = moles

In a mixture, n is the total moles (Sum of each mol, from each gas)

Moles = Mass / Molar mass

Moles He = 0.738 g / 4g/m = 0.184 moles

Moles N₂ = 8.98 g / 28g/m = 0.320 moles

0.184 m + 0.320m = 0.504 moles

P . 7.03L = 0.504m . 0.082L.atm/ mol.K . 290K

P = (0.504m . 0.082L.atm/ mol.K . 290K) /7.03L

P = 1.70 atm - This is the total pressure.

To know the partial pressure of N₂ we can apply, the molar fraction:

Moles of N₂ / Total moles = Pressure N₂ / Total pressure

0.320m / 0.504m = Pressure N₂ / 1.70atm

(0.320m / 0.504m) . 1.70atm = Pressure N₂

1.08atm = Pressure N₂

8 0

3 years ago

In an AP, sum of four consecutive terms is 28 and their sum of their squares is 276. Find the four numbers.

Aleks [24]

Four Consecutive terms are written as a-3, a-1, a+1,a+3. So

Sum of Terms : 4a=28
a=7

So the terms are 4,6,8,10

Verification : 4^2+6^2+8^2+10^2
= 216

4 0

3 years ago

Why is potassium less reactive than silver

Reika [66]

Because potassium is a gas that can evolve

3 0

3 years ago

A student is instructed to design a device that can allow one user to hear a voice of another surer a distance of 5 kilometers w

Scorpion4ik [409]

Answer:

A device designed to transmit electromagnetic waves through the air should be developed.

6 0

3 years ago