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
Katyanochek1 [597]
3 years ago
5

What is the mole fraction of solute and the molal concentration for an aqueous solution that is 20.0% NaOH by mass?

Chemistry
1 answer:
never [62]3 years ago
8 0
Let's assume we have 100 grams of this solution, and therefore 20.0 grams of NaOH, and 80.0 grams of water.

NaOH has a molar mass of 40.00 grams/mole, so we can convert NaOH to moles: (20.0 grams of NaOH) * (1 mole NaOH/40.00 grams NaOH) = 0.500 moles NaOH.

Next, we have a molar mass of water of 18.02 g/mol, so we can convert water to moles:

80.0 grams H2O * (1 mole H2O/18.02 grams) = 4.44 moles H2O
The mole fraction of NaOH is the moles of NaOH over the total moles of all parts of the solution. Therefore:

(0.500 moles NaOH)/(0.500 moles + 4.44 moles) = 0.101
0.101 = mole fraction of solute

The molal concentration is defined as the number of moles of solute over the number of kilograms of solvent (water).
We have 0.500 moles of NaOH, and 0.0800 kg of water, so it becomes:
(0.500 moles NaOH)/(0.0800 kg H2O solvent) = 6.25 molal solution
You might be interested in
The reaction of nitrogen dioxide with fluorine
andrew-mc [135]

Answer:

Rate = 0.001615 Ms-1

Explanation:

2 NO2 + F2 --> 2 NO2F

The reaction is first order with respect to NO2 and also first order with respect to F2.

The rate law is given as;

Rate = k [NO2] [ F2]

k = 1.58E-4 M-1s-1

[NO2] = 2.84 M

[F2] = 3.60 M

Rate = ?

Inserting the values into the equation, we have;

Rate = 1.58E-4 * 2.84 * 3.60

Rate = 0.001615 Ms-1

4 0
3 years ago
Please help me with this. (: I'd appreciate it.
Soloha48 [4]

Answer:

The answer to your question is:  ΔH = -283 kJ/mol, first option

Explanation:

Reaction

                CO  +  O₂     ⇒     CO₂

ΔH = ∑H products - ∑H products

ΔH = -393.5 - (-110.5 + 0)

ΔH = -393.5 + 110.5

ΔH = -283 kJ/mol

4 0
3 years ago
Please help. Thank you!
scoray [572]

Answer: Uranium is a chemical element with atomic number 92 which means there are 92 protons and 92 electrons in the atomic structure. The chemical symbol for Uranium is U. Electron configuration of Uranium is [Rn] 5f3 6d1 7s2. Possible oxidation states are +3,4,5,6.

Explanation:

6 0
3 years ago
Read 2 more answers
Element A has an electronegativity of 0.8 and element B has an electronegativity of 3.0. Which statement best describes the bond
Advocard [28]

Answer:

C) The compound is largely ionic with A as the cation.

Explanation:

Pulings proposed the method to determine if the compound is ionic in nature or covalent in nature , by finding the difference between the electronegativity of the respective cation and anion .

The ion with higher electronegativity is the anion and the ion with lower electronegativity is the cation.

The electronegativity difference above 1.7 make the compound ionic in nature.

Hence, from the question ,

A is the cation and B is the anion.

And the electronegativity difference above 1.7 so the compound is ionic in nature.

8 0
3 years ago
Spheres of Earth Assignment Active Analyzing Sphere Interactions Explain how Earth's spheres may be affected by the droughts bro
Novay_Z [31]

During El Niño, changes in wind and ocean current patterns result in warm waters stretching across the whole Pacific Ocean. This extra heating causes changes in wind patterns, which causes atmosphere to react and change all the way from the ground to the edge of space around Earth.
4 0
3 years ago
Other questions:
  • A mineral sample is obtained from a region of the country that has high arsenic contamination. An elemental analysis yields the
    8·1 answer
  • Use the chart to determine which atom in the carbon–chlorine bond is assigned the delta negative charge. carbon atom chlorine at
    10·2 answers
  • Suppose that you want to compare the mass of a block of ice to its mass as liquid
    13·1 answer
  • what events and experiences lead bruno to gradually give up some of his innocence and see things differently
    7·1 answer
  • 8CO + 17H2 → C8H18 + 8H2O
    9·1 answer
  • Why is it important to have evidence to support conclusions? What is the impact of using weak or inaccurate evidence? describe a
    14·1 answer
  • In a reaction 4 NH3 + 5 O2 → 4 NO + 6 H2O, 1 mole of ammonia reacts with 2 moles of oxygen. Which of these is correct after the
    12·1 answer
  • Convert 650. J of energy to either kcal or cal
    13·1 answer
  • Determine whether each described process is endothermic or exothermic.
    6·1 answer
  • Sand is a particulate in nature​
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!