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
NISA [10]
3 years ago
15

11. The Ka for benzoic acid is 6.5 × 10–5. Calculate the pH of a 0.10 M benzoic acid solution.

Chemistry
1 answer:
Lisa [10]3 years ago
4 0

Answer:

2.6

Explanation:

Benzoic acid is a weak acid that dissociates according to the following equation.

C₆H₅COOH(aq) ⇄ C₆H₅COO⁻(aq) + H⁺(aq)

We can calculate the equilibrium concentration of H⁺ using the following expression.

[H⁺] = √(Ka × Ca)

where,

Ka is the acid dissociation constant

Ca is the initial concentration of the acid

[H⁺] = √(6.5 × 10⁻⁵ × 0.10) = 2.5 × 10⁻³

The pH is

pH = -log [H⁺] = - log 2.5 × 10⁻³ = 2.6

You might be interested in
A certain substance X has a normal freezing point of 5.6 °C and a molal freezing point depression constant Kf-7.78 °C-kg·mol-1.
Harrizon [31]

Answer:

27.60 g urea

Explanation:

The <em>freezing-point depression</em> is expressed by the formula:

  • ΔT= Kf * m

In this case,

  • ΔT = 5.6 - (-0.9) = 6.5 °C
  • Kf = 7.78 °C kg·mol⁻¹

m is the molality of the urea solution in X (mol urea/kg of X)

First we<u> calculate the molality</u>:

  • 6.5 °C = 7.78 °C kg·mol⁻¹ * m
  • m = 0.84 m

Now we<u> calculate the moles of ure</u>a that were dissolved:

550 g X ⇒ 550 / 1000 = 0.550 kg X

  • 0.84 m = mol Urea / 0.550 kg X
  • mol Urea = 0.46 mol

Finally we <u>calculate the mass of urea</u>, using its molecular weight:

  • 0.46 mol * 60.06 g/mol = 27.60 g urea

7 0
3 years ago
Which ones are right to this question?
Vitek1552 [10]

The average Kenectic energy

7 0
3 years ago
Which statement best describes the amount of catalyst that remains at the end of a reaction?
Ivenika [448]
I believe the correct answer is C. The amount of catalyst is the same at the end as at the beginning of the reaction. Catalysts can't be consumed by the reaction thus is not D.
7 0
3 years ago
Read 2 more answers
The most common source of copper (cu) is the mineral chalcopyrite (cufes2). how many kilograms of chalcopyrite must be mined to
tigry1 [53]

Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.

Solution : Given,

Mass of Cu = 300 g

Molar mass of Cu = 63.546 g/mole

Molar mass of CuFeS_2 = 183.511 g/mole

  • First we have to calculate the moles of Cu.

\text{ Moles of Cu}=\frac{\text{ Given mass of Cu}}{\text{ Molar mass of Cu}}= \frac{300g}{63.546g/mole}=4.7209moles

The moles of Cu = 4.7209 moles

From the given chemical formula, CuFeS_2 we conclude that the each mole of compound contain one mole of Cu.

So, The moles of Cu = Moles of CuFeS_2 = 4.4209 moles

  • Now we have to calculate the mass of CuFeS_2.

Mass of CuFeS_2 = Moles of CuFeS_2 × Molar mass of CuFeS_2 = 4.4209 moles × 183.511 g/mole = 866.337 g

Mass of CuFeS_2 = 866.337 g = 0.8663 Kg         (1 Kg = 1000 g)

Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.


3 0
3 years ago
From where do the placenta and umbilical cord develop?
Anastasy [175]
It’s either the first or second one

I think it’s the first one - the outer cells of the blastocyst
8 0
3 years ago
Read 2 more answers
Other questions:
  • A mass of the crucible (g) 88.000g
    9·1 answer
  • What is another word for the sound barrier?
    11·2 answers
  • What describes the change in Gibbs free energy (∆G) of a spontaneous reaction?
    8·1 answer
  • We’ve all heard of acid rain and its impact on the environment, the infrastructure, like roads and buildings, and on humans. If
    12·1 answer
  • 1. Three
    11·1 answer
  • 22. What is a comet?
    5·1 answer
  • Why is heat needed to get a reaction to occur
    8·2 answers
  • What happens to temperature when the frequency is increased and when the frequency is decreased
    7·1 answer
  • A sample of 4.5 moles of an unknown gas occupies a volume of 1.6L at 23.2atm, what is the ideal temperature in oC for this sampl
    15·1 answer
  • The uneven heating of the atmosphere by the sun's energy creates pressure
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!