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
Vladimir79 [104]
3 years ago
11

At 55.0 ∘C, what is the vapor pressure of a solution prepared by dissolving 78.4 g of LiF in 253 g of water? The vapor pressure

of water at 55.0 ∘C is 118 mmHg. Assume complete dissociation of the solute. Express your answer to three significant figures and include the appropriate units.
Chemistry
1 answer:
ddd [48]3 years ago
7 0

Answer:

82.5 mmHg

Explanation:

The vapor pressure of a solution that contains a non-volatile solute will depend on the mole fraction of the solvent and on the vapor pressure of the pure solvent at the same temperature.

P sol=  χsolvent ⋅ P∘solvent, where

Psol - the vapor pressure of the solution

χ solvent - the mole fraction of the solvent

P ∘solvent - the vapor pressure of the pure solvent

Now, the most important thing to realize here is that lithium fluoride,  

LiF , a soluble ionic compound, will dissociate completely in aqueous solution to form lithium cations and fluoride anions.

LiF (aq] → Li+(aq]  + F − (aq]

Notice that every mole of lithium fluoride produces one mole of lithium cations and one mole of fluoride anions.

This means that you get a total of two moles of ions for every one mole of lithium fluoride in the solution.

Use lithium fluoride's molar mass to determine how many moles would be found in the given sample

78.4g⋅ (1 mole LiF /25.94 g)  = 3.022 moles LiF

This means that the solution will contain

3.022 moles LiF ⋅  (2 moles ions /1 mole LiF)  = 6.044 moles ions

Now, water's mole fraction in this solution will be equal to the number of moles of water divided by the total number of moles present in the solution.

To get the number of moles of water, use its molar mass

253  g  ⋅  (1 mole H 2O / 18.015 g) = 14.044 moles H 2O

This means that water's mole fraction will be

χwater = 14.044 moles  / (14.044 +6.044 )moles = 0.6991

The vapor pressure of the solution will thus be

Psol= 0.6991  ⋅ 118 mmHg = 82.5 mmHg

You might be interested in
A student walks 2 km in 30 min what is the students average In km/h
horrorfan [7]

I think the answer the students average is 15 km?


8 0
3 years ago
How many grams of oxygen are in 5.3 moles of lactose? (Using percent composition)
Misha Larkins [42]
Hey Umm here you can search it honey bun
8 0
2 years ago
Two 10g blocks, one of copper and one of iron, were heated from 300 K to 400K (a temperature difference of 100 K).
vova2212 [387]

Energy absorbed by Iron block E (iron) = 460.5 J

Energy absorbed by Copper block E (Copper) = 376.8 J

<u>Explanation:</u>

To find the heat absorbed, we can use the formula as,

q = m c ΔT

Here, Mass = m = 10 g = 0.01 kg

ΔT = change in temperature = 400 - 300 = 100 K = 100 - 273 = -173 °C

c = specific heat capacity

c for iron = 460.5 J/kg K

c for copper = 376.8 J/kg K

Plugin the values in the above equation, we will get,

q (iron) = 0.01 kg × 460.5 J/kg K × 100 K

            = 460.5 J

q (copper) = 0.01 kg ×  376.8 J/kg K × 100 K

                 = 376.8 J

3 0
3 years ago
The balanced chemical equation for the reaction of copper (Cu) and silver nitrate (AgNO3) is shown below. Cu + 2AgNO3 2Ag + Cu(N
Luden [163]
1 mol Cu - 2 mol Ag
x             - 0.854 mol Ag

x=0.854*1/2=0.427 

0.427 mol Cu
5 0
3 years ago
Read 2 more answers
What is the pun when I go from here to there quickly on foot
zlopas [31]
1. A type of mens cologne
2. A police officers boss
3. When i go from here to there quickly on foot

Idk thats what google said
6 0
3 years ago
Other questions:
  • Why are both absolute dating and relative dating used to determine the age of fossils?
    5·2 answers
  • Which of the following explains the conservation of mass during cellular respiration?
    11·1 answer
  • Equations can be balanced by using the half-reaction method. Which step should be completed immediately after finding the oxidat
    11·2 answers
  • ________________ is 'The movement of a liquid up a narrow tube due to adhesive affects.'
    5·1 answer
  • Which is a positive effect of the technology advance of going from a compass to a gps
    5·1 answer
  • What is the formula mass (molar mass) of sucrose (C12H22O11)?​
    5·1 answer
  • How many moles of HNO3 are present if 4.90×10−2 mol of Ba(OH)2 was needed to neutralize the acid solution?
    6·1 answer
  • Circle the letter of the best answer.
    12·1 answer
  • How many electrons elements are present in period 2 ?​
    10·2 answers
  • Consider the following thermochemical reaction for kerosene:
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!