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
yarga [219]
3 years ago
9

If 185 g of KBr are dissolved in 1.2 kg of water, what would be the expected change in boiling point? The boiling point constant

for water (Kb) is 0.51 °C/m.
A. 0.66°C
B. 0.85°C
C. 1.3°C
D. 3.1°C
Chemistry
2 answers:
Feliz [49]3 years ago
8 0
When a solute is added to a solvent, the vapor pressure of the solvent (above the resulting solution) is less than the vapor pressure above the pure solvent. The boiling point of a solution, then, will be greater than the boiling point of the pure solvent because the solution (which has a lower vapor pressure) will need to be heated to a higher temperature in order for the vapor pressure to become equal to the external pressure (i.e., the boiling point).

The boiling point of the solvent above a solution changes as the concentration of the solute in the solution changes (but it does not depend on the identity of either the solvent or the solute(s) particles (kind, size or charge) in the solution).

Non-Volatile Solutes

The boiling point of the solvent above a solution will be greater than the boiling point of the pure solvent whether the solution contains a non-volatile solute or a volatile solute. However, for simplicity, only non-volatile solutes will be considered here.

Experimentally, we know that the change in boiling point of the solvent above a solution from that of the pure solvent is directly proportional to the molal concentration of the solute:

T = Kbm

where:

        T is the change in boiling point of the solvent,
        Kb is the molal boiling point elevation constant, and
        m is the molal concentration of the solute in the solution.

Note that the molal boiling point elevation constant, Kb, has a specific value depending on the identity of the solvent.

solventnormal boiling point, oCKb, oC m-1water100.00.512acetic acid118.13.07benzene80.12.53chloroform61.33.63nitrobenzene210.95.24

The following graph shows the normal boiling point for water (solvent) as a function of molality in several solutions containing sucrose (a non-volatile solute). Note that the normal boiling point of water increases as the concentration of sucrose increases.



The Microscopic View

The figure below shows a microscopic view of the surface of pure water. Note the interface between liquid water (below) and water vapor (above).



Non-Volatile Solutes

The figures below illustrate how the vapor pressure of water is affected by the addition of the non-volatile solute, NaCl.

Note that:

there are fewer water molecules in the vapor (i.e., lower vapor pressure) above the NaCl solution than in the vapor above pure water, and

the boiling point of the NaCl solution will be greater than the boiling point of pure water.


0.85°C.
expected change in boiling point The boiling point constant for water

Fudgin [204]3 years ago
6 0

Answer:

ΔTb = 0.66 C

Explanation:

Given

Mass of KBr = 185 g

Mass of water = 1.2 kg

Kb = 0.51 C/m

Explanation:

The change in boiling point (ΔTb) is given by the product of molality (m) of the solution and the boiling point constant (Kb)

\Delta T_{b}= K_{b}* m

Molality = \frac{moles\ KBr}{Kg\ water} \\\\moles KBr = \frac{mass\ KBr}{Mol.wt\ KBr} = \frac{185}{119} = 1.555\\\\Molality (m) = \frac{1.555 }{1.2} =1.296 m\\

[tex]\Delta T_{b}= 0.51 C/m * 1.296 m = 0.66 C[\tex]

You might be interested in
When calcium carbonate reacts with hydrochloric acid, calcium ions are transferred to the solution. Write only one net ionic equ
nika2105 [10]

Answer:

In conclusion, the net ionic equation for the reaction between calcium carbonate and hydrochloric acid is CaCO3 solid plus two H+ aqueous react to form Ca2+ aqueous plus CO2 gas plus H2O liquid.

6 0
3 years ago
Fill in the blank, please help. (55 points)
Degger [83]
The answer would be evaporation takes place at the surface of an ocean, lake, stream, or other body of water
7 0
3 years ago
Which elements, when they have to, can have more than
inn [45]
Elements in the third row can break the octet rule
6 0
3 years ago
Iron reacts with cl2 according to the equation 2 fe(s) + 3 cl2(g) ? 2 fecl3(s). how many moles of cl2 is needed to react with 4.
IceJOKER [234]
2Fe + 3Cl₂ ---> 2FeCl₃

4.4mol of Fe, you have a 2:3 ratio of Fe to Cl₂ so divide 4.4/2 = 2.2 and multiply by three 2.2 x 3 = 6.6mol of Cl₂

hope that helps :)
8 0
3 years ago
Read 2 more answers
In which state do molecules have the highest kinetic energy? in the liquid state in the solid state in the gaseous state during
Dvinal [7]
It depends on the substance,but for most substance it is in the gaseous state.
5 0
3 years ago
Read 2 more answers
Other questions:
  • Calculate the amount of heat required to completely sublime 96.0 g of solid dry ice (co2) at its sublimation temperature. the he
    7·1 answer
  • Which best defines nitrogen fixation
    5·1 answer
  • The inca "City of the sun"was ​
    6·1 answer
  • Absolute zero is what temperature on the fahrenheit scale?
    12·1 answer
  • Which of the samples pictured is most likely a nonmetal?
    5·1 answer
  • Completely classify jet fuel.
    8·1 answer
  • Human bone does not contain?
    5·1 answer
  • Two aqueous NaCl solutions of equal volume and concentration were kept in flasks and held at different temperatures. The two sol
    10·1 answer
  • How can the percent yield be used to determine the actual yield of a chemical reaction
    9·1 answer
  • This illustration shows a kind of animal that is a free living organism. what is the common name of this organism?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!