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
Jobisdone [24]
3 years ago
13

Consider a 125 mL buffer solution at 25°C that contains 0.500 mol of hypochlorous acid (HOCl) and 0.500 mol of sodium hypochlori

te (NaOCl). What will be the pH of this buffer solution after adding 0.341 mol of HCl? The Ka of hypochlorous acid is 2.9 x 10-8 . Assume the change in volume of the buffer solution is negligible
Chemistry
1 answer:
Helga [31]3 years ago
6 0

Answer:

pH = 6.82

Explanation:

To solve this problem we can use the<em> Henderson-Hasselbach equation</em>:

  • pH = pKa + log\frac{[NaOCl]}{[HOCl]}

We're given all the required data to <u>calculate the original pH of the buffer before 0.341 mol of HCl are added</u>:

  • pKa = -log(Ka) = -log(2.9x10⁻⁸) = 7.54
  • [HOCl] = [NaOCl] = 0.500 mol / 0.125 L = 4 M
  • pH = 7.54 + log \frac{4}{4}
  • pH = 7.54

By adding HCl, w<em>e simultaneously </em><u><em>increase the number of HOCl</em></u><em> and </em><u><em>decrease NaOCl</em></u>:

  • pH = 7.54 + log\frac{[NaOCl-HCl]}{[HOCl+HCl]}
  • pH = 7.54 + log \frac{(0.500mol-0.341mol)/0.125L}{(0.500mol+0.341mol)/0.125L}
  • pH = 6.82
You might be interested in
(a) 4.64 x 1024 atoms Bi into grams
nexus9112 [7]

Answer:

1610.7 g is the weigh for 4.64×10²⁴ atoms of Bi

Explanation:

Let's do the required conversions:

1 mol of atoms has 6.02×10²³ atoms

Bi → 1 mol of bismuth weighs 208.98 grams

Let's do the rules of three:

6.02×10²³ atoms are the amount of 1 mol of Bi

4.64×10²⁴ atoms are contained in (4.64×10²⁴ . 1) /6.02×10²³ = 7.71 moles

1 mol of Bi weighs 208.98 g

7.71 moles of Bi must weigh (7.71 . 208.98 ) /1 = 1610.7 g

5 0
3 years ago
Pls help i beg
marusya05 [52]

Answer:

The increasing order of conductivity is O< Ge< Mn.

Explanation:

Electrical conductivity is defined as the measure of the ability of a material to conduct electrical current through it. The conductivity depends on the atomic and molecular structure of the material.

Metals are good conductors because they have a structure with many electrons with weak bonds, and this allows their movement instead non-metals have between four and eight valence electrons, which lack this tendency.

The conductivity increases in the periodic table from top to bottom and from right to left.

oxygen is a nonmetal therefore it is a bad conductor.

Germanium is a metalloid whose conductivity is greater than a nonmetal and worst than a metal.

Manganese is a metal,in this case, it is a good conductor.

4 0
3 years ago
A simple machine produces 25 joules of output work for every 50 joules of input work . What is the efficiency of this machine ?
nataly862011 [7]
2:1, output is half the input
8 0
3 years ago
What is the mass of 2.5 mol of ca, which has a molar mass of g/mol
swat32
Atomic mass Ca = 40 a.m.u

1 mole Ca ----------- 40 g
2.5 mols Ca -------- ( mass Ca )

Mass Ca = 2.5 x 40 / 1

Mass Ca = 100 / 1

= 100 g of Ca

hope this helps!
3 0
3 years ago
If 190dm of hydrogen gas collected at 20°c and 760mmHg .Calculate it's volume at stp (standard pressure=760mmHg
Andrei [34K]

Answer:

177.1 L

Explanation:

The excersise can be solved, by the Ideal Gases Law.

P . V = n . R . T

In first step we need to determine the moles of gas:

We convert T° from, C° to K → 20°C + 273 = 293K

We convert P from mmHg to atm → 760 mmHg = 1atm

1Dm³ = 1L → 190L

We replace: 190 L . 1 atm = n . 0.082 . 293K

(190L.atm) / 0.082 . 293K = 7.91 moles.

We replace equation at STP conditions (1 atm and 273K)

V = (n . R .T) / P

V = (7.91 mol . 0.082 . 273K) / 1atm = 177.1 L

We can also make a rule of three:

At STP conditions 1 mol of gas occupies 22.4L

Then, 7.91 moles will be contained at (7.91 . 22.4) /1 = 177.1L

3 0
3 years ago
Other questions:
  • Radiocarbon dating is useful for estimating the _______ of a material
    9·2 answers
  • Calculate the mass (in grams) of silver in 10.0 grams of silver sulfide ag2s
    11·1 answer
  • For Carbon, which sublevel has unpaired electrons?<br> ASAP
    6·1 answer
  • Which of the following is formed when a barium atom achieves an octet?
    9·1 answer
  • Which substance can not be broken down by a chemical change?
    10·1 answer
  • A balloon with a volume of 2.0 L is filled with a gas at 3 atmospheres. If the pressure is reduced to 0.5 atmospheres without a
    8·1 answer
  • Which of the following is an
    7·2 answers
  • Silicon is a metalloid element commonly found in Earth's crust. It helps form many different compounds, which have a variety of
    7·1 answer
  • Please help!!!
    15·1 answer
  • A CHM 111 student completing Part B recorded the mass of several pieces of dry metal as
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!