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
ch4aika [34]
2 years ago
7

If you have an aqueous solution that is 13.5 % Na3PO4 by mass, what is the molality of Na3PO4 in the solution?

Chemistry
1 answer:
Nata [24]2 years ago
7 0

Considering the definition of percentage by mass and molality, the molality of Na₃PO₄ in the solution is 0.948 \frac{moles}{kg}.

  • <u><em>Percentage by mass</em></u>

The percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.

In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.

The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:

percentage by mass=\frac{mass of solute}{mass of solution}x100

  • <u><em>Molality</em></u>

Molality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.

The Molality of a solution is determined by the expression:

molality=\frac{number of moles of solute}{kilograms of solvent}

  • <u><em>This case</em></u>

Considering 100 grams as a sample of the solution, then the value of the percentage of concentration given indicates that  13.5 g correspond to Na₃PO₄.

Remember that percent concentration by mass is calculated using the mass of solute and the mass of the solution, which includes both the solute and the solvent. Then:

mass solution= mass solute + mass solvent

100 g= 13.5 g + mass solvent

100 g - 13.5 g= mass solvent

<u><em>86.5 g= mass solvent</em></u>

Then, you know:

  • number of moles of solvent=  13.5 gramsx\frac{1 mole}{163.94 grams} =0.082 moles being 163.94 \frac{grams}{mole}the molar mass of Na₃PO₄, this is the amount of mass a substance contains in one mole.
  • mass of solvent= 86.5 grams= 0.0865 kg (being 1000 g= 1 kg)

Then, replacing in the definition of molality:

molality=\frac{0.082 moles}{0.0865 kg}

Solving:

molality= 0.948 \frac{moles}{kg}

Finally, the molality of Na₃PO₄ in the solution is 0.948 \frac{moles}{kg}.

Learn more about:

  • mass percentage:
  1. brainly.com/question/19168984?referrer=searchResults
  2. brainly.com/question/18646836?referrer=searchResults
  3. brainly.com/question/20037730?referrer=searchResults
  4. brainly.com/question/25148948
  • molality
  1. brainly.com/question/20366625?referrer=searchResults
  2. brainly.com/question/4580605?referrer=searchResults

You might be interested in
PLEASE!!! I NEED HELP ASAP!!
Lana71 [14]
W=m₁/m₀=2^(-t/T)

t=4.6·10⁹ years
T=5·10¹⁰ years

w=2^(-4.6·10⁹/5·10¹⁰)

w=0.9382
w=93.82%

7 0
2 years ago
Read 2 more answers
Which of the following is an example of a parasite?
snow_tiger [21]
C
a parasite is an organism that lives inside a host and benefits from taking away nutrients at the others expense
7 0
2 years ago
Read 2 more answers
Which is the following will have the highest vapor pressure
Alexus [3.1K]

There is no list, but possibly evaporation.

8 0
2 years ago
Liquid helium boils at –268.93 °C. What is the boiling point of helium on the Kelvin temperature scale?
BARSIC [14]

In order to change celcius to kelvin always add 73 to it leaving you with -195.93

4 0
3 years ago
Read 2 more answers
Which of the following acids is the WEAKEST? The acid is followed by its Ka value.HF, 3.5 × 10^-4HNO2, 4.6 × 10^-4HCN, 4.9 × 10^
Mila [183]

Answer:

HCN

Explanation:

There are several factors that can tell us when an acid is stronger than another, which are the following:

1. The Polarity of the X - H Bond

2. Size of the X atom.

3. Charge on the acid.

4. Oxidation state of the central atom

5. Values of Ka and pKa.

From all of this factors, we can see that the exercise is already giving us values of Ka, and also we have different types of acid, not only with the form H - X

So, we will base the force of an acid by it's pKa value.

The pKa value which is calculated with the expression:

pKa = -logKa

pKa is a value that indicates how strong is the acid you are working with. This value can vary depending on factors such the charge of the acid. I f this charge can be easily distributed in resonance structures, the compound is more acidic, and therefore the pKa value is lower.

The lower the pKa, the more acidic the compound is.

So calculating the pKa on every structure we have:

HF: pKa = -log(3.5x10^-4) = 3.46

HNO2: pKa = -log(4.6x10^-4) = 3.34

HCN: pKa = -log(4.9x10^-10) = 9.31

HCOOH: pKa = -log(1.8x10^-4) = 3.74

HClO2: -log(1.1x10^-2) = 1.96

So according to all this values, we can conclude that the weakest acid is the HCN

4 0
3 years ago
Other questions:
  • How many elements does the periodic table have quick my wifi not working help please
    15·1 answer
  • Radon-219 decays to radon-218 by releasing... a. a positron b.a muon O c. a neutron O d. an electron O e. a proton
    10·1 answer
  • Describe the profile you would expect for a biological catalyst. Complete the sentences to explain why an enzyme is different th
    11·1 answer
  • TRY H Vele
    7·1 answer
  • When atoms come together, there is _______ between the negative electrons clouds.
    10·1 answer
  • Which statements describe the principles of the big bang theory? Check all that apply.
    12·2 answers
  • How many valence electrons do elements in the same family as Aluminum contain?
    8·1 answer
  • Hydrocarbons separated by fractional distillation of petroleum can be cracked to make
    15·1 answer
  • Fish need about 5 ppm oxygen dissolved in water to survive. Will water with 5 mg oxygen per
    11·1 answer
  • What is the treatment and disposal of Mercury<br>​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!