Chemistry, 29.07.2019 01:30 jetblackcap

Calculate the percent ionization of formic acid (hco2h) in a solution that is 0.311 m in formic acid and 0.189 m in sodium formate (nahco2). the ka of formic acid is 1.77 ⋅ 10-4.

Answers: 1

Show answers

Answers

0.094%

Explanation:

1) Equilibrium chemical equation:

Only the ionization of the formic acid is the important part.

HCOOH(aq) ⇄ HCOO⁻(aq) + H⁺(aq).

2) Mass balance:

                   HCOOH(aq) HCOO⁻(aq) H⁺(aq).

Start 0.311               0.189

Reaction       - x    +x                   +x

Final             0.311 - x    0.189 + x    x

3) Acid constant equation:

Ka = [HCOO-] [N+] / [HCOOH] = (0.189 + x) x / (0.311 -x)

= (0.189 + x )x / (0.311 - x) = 0.000177

4) Solve the equation:

You can solve it exactly (it will lead to a quadratic equation so you can use the quadratiic formula). I suggest to use the fact that x is much much smaller than 0.189 and 0.311.

With that approximation the equation to solve becomes:

0.1890x / 0.311 = 0.000177, which leads to:

x = 0.000177 x 0.311 / 0.189 = 2.91 x 10⁻⁴ M

5) With that number, the percent of ionization (alfa) is:

percent of ionization = (moles ionized / initial moles) x 100 =

percent ionization = (concentration of ions / initial concentration) x 100 =

percent ionization = (0.000291 / 0.311)x 100 = 0.0936% = 0.094%

Answer from: Quest

it should be p1 v1 = p2 v2

Answer from: Quest

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

Write 15 uses of a mercury barometer along with its characterestics

Another question on Chemistry

Chemistry, 22.06.2019 12:30

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

Answers: 1

Answer

Chemistry, 22.06.2019 15:30

The reactions of photosynthesis occur in the of plant cell? a.mitochondria. b. lysosomes. c. chloroplasts. d. chlorophyll

Answers: 1

Answer

Chemistry, 22.06.2019 17:00

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.

Answers: 1

Answer

Chemistry, 23.06.2019 08:20

At which temperature would a reaction with ah= -220 kj/mol and as=-0.05 kj/(mol-k) be spontaneous?

Answers: 2

Answer

You know the right answer?

Calculate the percent ionization of formic acid (hco2h) in a solution that is 0.311 m in formic acid...

Questions

Engineering, 19.01.2021 16:50

Why do carpenters require knowledge of mathematics? They have to cut materials to specification. They have to prepare bills....