1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
emmainna [20.7K]
3 years ago
9

Be sure to answer all parts. What is the [H3O+] and the pH of a buffer that consists of 0.26 M HNO2 and 0.89 M KNO2? (K, of HNO2

= 7.1 x 10-4) fH 0+1= x 10 M (Enter your answer in scientific notation.) pH =
Chemistry
1 answer:
Aleksandr-060686 [28]3 years ago
4 0

Answer : The H_3O^+ ion concentration is, 1.12\times 10^{-3}M and the pH of a buffer is, 2.95

Explanation : Given,

K_a=7.1\times 10^{-4}

Concentration of HNO_2 (weak acid)= 0.26 M

Concentration of KNO_2 (conjugate base or salt)= 0.89 M

First we have to calculate the value of pK_a.

The expression used for the calculation of pK_a is,

pK_a=-\log (K_a)

Now put the value of K_a in this expression, we get:

pK_a=-\log (7.1\times 10^{-4})

pK_a=4-\log (7.1)

pK_a=3.15

Now we have to calculate the pH of the solution.

Using Henderson Hesselbach equation :

pH=pK_a+\log \frac{[Salt]}{[Acid]}

pH=pK_a+\log \frac{[KNO_2]}{[HNO_2]}

Now put all the given values in this expression, we get:

pH=3.15+\log (\frac{0.89}{0.26})

pH=2.95

The pH of a buffer is, 2.95

Now we have to calculate the H_3O^+ ion concentration.

pH=-\log [H_3O^+]

2.95=-\log [H_3O^+]

[H_3O^+]=1.12\times 10^{-3}M

The H_3O^+ ion concentration is, 1.12\times 10^{-3}M

You might be interested in
If a steel container holds 3.50 moles of hydrogen gas and 3.50 moles of helium gas, and the total pressure is 4.00 atm., what is
Sunny_sXe [5.5K]

Answer:

1. Partial pressure of H₂ = 2 atm

2. Partial pressure of He = 2 atm

Explanation:

The following data were obtained from the question:

Mole of H₂ = 3.50 moles

Mole of He = 3.50 moles

Total pressure (Pₜ) = 4 atm

Partial pressure of H₂ =?

Partial pressure of He =?

Next, we shall determine the mole fraction of each gas this can be obtained as follow:

Mole of H₂ = 3.50 moles

Mole of He = 3.50 moles

Total mole = Mole of H₂ + Mole of He

Total mole = 3.50 + 3.50

Total mole = 7 moles

Mole fraction of H₂ = mole of H₂ / Total mole

Mole fraction of H₂ = 3.5/7

Mole fraction of H₂ = 0.5

Mole fraction of He = mole of He / Total mole

Mole fraction of He = 3.5/7

Mole fraction of He = 0.5

1. Determination of the partial pressure of H₂.

Mole fraction of H₂ = 0.5

Total pressure (Pₜ) = 4 atm

Partial pressure of H₂ =?

Partial pressure of H₂ = Mole fraction of H₂ × Pₜ

Partial pressure of H₂ = 0.5 × 4

Partial pressure of H₂ = 2 atm

2. Determination of the partial pressure of He.

Total pressure (Pₜ) = 4 atm

Partial pressure of H₂ = 2 atm

Partial pressure of He =?

Total pressure (Pₜ) = Partial pressure of H₂ + Partial pressure of He

4 = 2 + Partial pressure of He

Collect like terms

Partial pressure of He = 4 – 2

Partial pressure of He = 2 atm

6 0
3 years ago
How many grams of steam at 100 °C would be required to raise the temperature
Alex777 [14]

The mass of steam required to raise the temperature of water is 3.5 g.

The given parameters;

  • <em>mass of the benzene, = 47.6</em>
  • <em>initial temperature of the benzene, = 5.5 ⁰C</em>
  • <em>final temperature of the benzene = 30 ⁰C</em>

The molar mass of Benzene = 78.11 g/mol

The molar mass of water = 18 g/mol

The number of moles of the Benzene is calculated as follows;

n = \frac{47.6}{78.11} = 0.61 \ mole

The mass of steam required is calculated as follows;

<em>heat lost by steam = heat absorbed by benzene</em>

<em />

\frac{m}{18} \times 40.7 \times 10^3 = 47.6(1.63)(30-5.5) \ + \ 0.61 \times 9.87 \times 10^3\\\\2261.11 m = 7921.61\\\\m = \frac{7921.61}{2261.11} \\\\m = 3.5 \ g

Thus, the mass of steam required to raise the temperature of water is 3.5 g.

Learn more here:brainly.com/question/14963365

3 0
3 years ago
A 40 g sample of sucrose contains 16.8 g of carbon. what is the mass
NemiM [27]

Answer:

Thus 100.00 g of sucrose contains 42.11 g of carbon, 6.48 g of hydrogen, and 51.41 g of oxygen; to two decimal places, the percent composition of sucrose is indeed 42.11% carbon, 6.48% hydrogen, and 51.41% oxygen.

Explanation:

Hope this helps, leave a heart ❤️

3 0
3 years ago
Identify the electrophilic site in the following molecule, CH_3CH_2NHCH_2CH_3. (A) H (B) N (C) CH_2 (D) CH_3 (E) there is no ele
Serhud [2]

Answer:

(C) CH_2

Explanation:

An electrophile is an atom that loves electron. For an atom to be able to pull electrons closer to itself, it must be electron deficient and with a partial positive charge.

From the structure give, N is a highly electronegative atom and it is a nucleophile. This implies it loves the nucleus which is positively charged.

The Carbon atom attached to it is an electrophile because it has a lower electronegativity thereby leaving a partial positive charge on it. Therefore, the carbon will be attracted to the nucleophile.

4 0
3 years ago
Suppose you have a system made up of water only, with the container and everything beyond being the surroundings. Consider a pro
Airida [17]

Answer:

Yes

Explanation:

The possibility of evaporating and condensing is a proof of reversible reaction

8 0
3 years ago
Read 2 more answers
Other questions:
  • Which statement illustrates the difference between a chemical reaction and a nuclear reaction?
    5·1 answer
  • An oscilloscope is a machine that gives a picture of a sound wave. Low-pitched sounds have wide waves, and high-pitched sounds h
    10·2 answers
  • The U.S. requires automobile fuels to contain a renewable component. The fermentation of glucose from corn produces ethanol, whi
    5·1 answer
  • How many particles are present in one mole of particles?
    6·1 answer
  • Can someone help me with this one?
    6·1 answer
  • The prefix centi- means
    11·2 answers
  • What is the volume, in liters, of a 0.2 M solution containing 8.5 grams of AgNO3?
    5·1 answer
  • HELP ME WITH THIS PLSSSSS
    8·1 answer
  • Please help!!!!!!!!!!!!!!
    14·1 answer
  • Use the drop-down menus to determine the changes of<br> state that are missing from the triangle.
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!