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
Nataly [62]
3 years ago
6

What is the pH of a solution prepared by dissolving 0.140 g of potassium hydroxide in sufficient pure water to prepare 250.0 ml

of solution
Chemistry
1 answer:
Dimas [21]3 years ago
7 0

Answer:

pH= 12

Explanation:

Potassium hydroxide (KOH) is a strong base, so it dissociates completely in water by giving OH⁻ anions as follows:

KOH⇒ K⁺ + OH⁻

Since dissociation is complete, it is assumed that the concentration of OH⁻ is equal to the initial concentration of KOH:

[OH⁻]= [KOH]

In order to find the initial concentration of KOH, we have to divide the mass (0.140 g) into the molecular weight of KOH (Mw):

Mw (KOH)= K + O + H = 39 g/mol + 16 g/mol + 1 g/mol = 56 g/mol

moles KOH: mass/Mw= 0.140 g/(56 g/mol) = 2.5 x 10⁻³ moles

The molality of the solution is the number of moles of KOH per liter of solution:

V= 250.0 ml x 1 L/1000 ml= 0.250 L

M = (2.5 x 10⁻³moles)/(0.250 L)= 0.01 M

Now, we calculate pOH:

pOH = -log [OH⁻]= - log [KOH]= -log (0.01) = 2

Finally, we calculate pH from pOH:

pH + pOH = 14

⇒pH = 14 - pOH= 14 -2 = 12

You might be interested in
Compare your predicted ranking of the objects’ volumes with their final ranking based on their measurements. What are the advant
Schach [20]

Answer:

Since its data sample can be quantified using fixed numerical parameters, quantitative observation yields more accurate results than qualitative observation and it is suitable for statistical investigations.

Explanation:

8 0
3 years ago
How do the properties of a compound like h2o or nacl illustrate the concept of emergent properties?
Softa [21]

Answer and explanation;

Na - metal

Cl - poisonous gas

NaCl - cyrstaline solid that is edible

An emergent property is a property which a collection or complex system has, but which the individual members do not.  

Water emergent properties: cohesion & adhesion, versatile solvent, temperature moderation, freezing.

The properties of a compound can be very different from the properties of the elements that make them, for example, Sodium is an explosive metal, and  Chlorine is a toxic gas, however, sodium chloride is a Delicious table salt!

4 0
3 years ago
Which of the following is NOT a property of an acid
ipn [44]
The answer is B. Acid turns blue litmus paper to red
4 0
3 years ago
Density of water calculation using a 10 mL graduated cylinder
matrenka [14]

Answer:

Average density of the liquid = 0.992 g/mL

Explanation:

Density = mass/volume

mass of liquid = (mass of liquid + mass of cylinder) - mass of cylinder

Trial 1: mass of liquid = 19.731 - 9.861 = 9.87

volume of liquid = 10 mL

density of liquid = 9.87 g / 10 mL = 0.987 g/mL

Trial 2: mass of liquid = 19.831 - 9.861 = 9.97

volume of liquid = 10 mL

density of liquid = 9.97 g / 10 mL = 0.997 g/mL

Trial 3: mass of liquid = 19.831 - 9.861 = 9.97

volume of liquid = 10 mL

density of liquid = 9.97 g / 10 mL = 0.997 g/mL

Trial 4: mass of liquid = 19.771 - 9.861 = 9.91

volume of liquid = 10 mL

density of liquid = 9.91 g / 10 mL = 0.991 g/mL

Trial 5: mass of liquid = 19.751 - 9.861 = 9.89

volume of liquid = 10 mL

density of liquid = 9.89 g / 10 mL = 0.989 g/mL

Average density = (0.987 + 0.997 + 0.997 + 0.991 + 0.989)/5 = 4.961/5

Average density of the liquid = 0.992 g/mL

8 0
3 years ago
Which process would most effectively separate two liquids with different molecular polarities?
Vlad1618 [11]
Answer is distillation.

the less polar liquid will distill faster at lower temperature compared to the polar liquid
6 0
3 years ago
Read 2 more answers
Other questions:
  • A 10 gram sample of material, a, was placed in water. four grams of it, b, did not dissolve, even after being separated and plac
    15·1 answer
  • What mass of xenon tetrafluoride, xef 4 , has the same number of fluorine atoms as 25.0 g of oxygen difluoride, of2?
    7·2 answers
  • How many atoms make up this compound ? Help asap
    7·2 answers
  • Which of the following quantities contains the greatest number of particles?
    12·2 answers
  • Sodium chloride (NaCl) is the chemical name for table salt and potassium chloride (KCl) is a common salt substitute. Using the p
    11·1 answer
  • Which is the atomic number of an atom that forms an ion with 18 electrons and a charge of 2+?
    14·1 answer
  • True or false sodium chloride is an organic molecule
    13·1 answer
  • Is there a relationship between the locations of earthquake, volcanoes, and plate boundaries? If so, describe the relationship.
    12·1 answer
  • 6. This particle has no charge<br> protons<br> neutrons<br> electrons
    14·2 answers
  • How many grams are in 0.787 moles of kcn
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!