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
Shtirlitz [24]
2 years ago
12

Determine the boiling point of a 3.70 m solution of phenol in benzene. Benzene has a boiling point of 80.1°C and a boiling point

elevation constant of 2.53°C•kg/mol.
Chemistry
1 answer:
xeze [42]2 years ago
8 0

Answer: The boiling point of a 3.70 m solution of phenol in benzene is 89.5^0C

Explanation:

Elevation in boiling point:

\Delta T_b=i\times k_b\times m

where,

\Delta T_b = change in boiling point

i= vant hoff factor = 1 (for benzene which is a non electrolyte )

k_b = boiling point constant = 2.53^0C/kgmol

m = molality = 3.70

T_{solution}-T_{solvent}=i\times k_b\times m

T_{solution}-80.1^0C=1\times 2.53\times 3.70

T_{solution}=89.5^0C

Thus  the boiling point of a 3.70 m solution of phenol in benzene is 89.5^0C

You might be interested in
The following questions pertain to a system contains 122 g CO(g) in a 0.400 L container at -71.2 degrees C.
Korolek [52]

Answer:

a. P = 182 atm

b. due to daviation from ideal gas behavior

Explanation:

Data Given:

amount of CO = 122g

Volume of CO = .400 L

Temperature of CO = -71.2°C

Convert the temperature to Kelvin

T = °C + 273

T = -71.2 + 273

T = 201.8 K

a. Calculate the pressure exerted by the CO(g) in this system using the ideal gas equation (P) = ?

Solution:

To calculate Pressure by using ideal gas formula

                        PV = nRT

Rearrange the equation for Pressure

                       P = nRT / V . . . . . . . . . (1)

where

P = pressure

V = Volume

T= Temperature

n = Number of moles

R = ideal gas constant = 0.08206 L.atm / mol. K

For this we have to know the mole of the gas and the following formula will be used

                no. of moles = mass in grams / molar mass . . . . . . (2)

Molar mass of CO = 12 + 16 = 28 g/mol

Put values in equation 2

                  no. of moles = 122 g / 28 g/mol

                  no. of moles = 4.4 mol

Now put the value in formula (1) to calculate Pressure for CO

        P = 4.4 x 201.8 K x 0.08206 (L.atm/mol. K) / 0.400 L

          P = 182 atm

So the pressure will be 182 atm

__________

b. Data Given:

Actual pressure exerted by CO = 145 atm

expected pressure exerted by CO = 182 atm

why the actual pressure is less than what would be expected = ?

Explanation:

This is because of the deviation from ideal behavior of real gases.

The real gases approaches to ideal behavior under very high temperature and very low pressure.

But CO deviate from ideal behavior to give expected value for pressure, because it behave at high pressure and low temperature.

This non-ideal behavior is due to two postulate of ideal behavior

• gas molecules have negligible volume

• Gas molecules have negligible inter-molecular interaction

but these postulates not obeyed under real condition. so we calculated the pressure using ideal condition values for gas and obtained the expected value for pressure but the actual pressure value was detected under normal condition.

4 0
3 years ago
Many different parts of the brain work together to encode, store, and retrieve information as needed. The diagram below indicate
a_sh-v [17]

Answer:

Are memories stored in just one part of the brain, or are they stored in many different parts of the brain? Karl Lashley began exploring this problem, about 100 years ago, by making lesions in the brains of animals such as rats and monkeys. He was searching for evidence of the engram: the group of neurons that serve as the “physical representation of memory” (Josselyn, 2010). First, Lashley (1950) trained rats to find their way through a maze. Then, he used the tools available at the time—in this case a soldering iron—to create lesions in the rats’ brains, specifically in the cerebral cortex. He did this because he was trying to erase the engram, or the original memory trace that the rats had of the maze.

Lashley did not find evidence of the engram, and the rats were still able to find their way through the maze, regardless of the size or location of the lesion. Based on his creation of lesions and the animals’ reaction, he formulated the equipotentiality hypothesis: if part of one area of the brain involved in memory is damaged, another part of the same area can take over that memory function (Lashley, 1950). Although Lashley’s early work did not confirm the existence of the engram, modern psychologists are making progress locating it. Eric Kandel, for example, spent decades working on the synapse, the basic structure of the brain, and its role in controlling the flow of information through neural circuits needed to store memories (Mayford, Siegelbaum, & Kandel, 2012).

Many scientists believe that the entire brain is involved with memory. However, since Lashley’s research, other scientists have been able to look more closely at the brain and memory. They have argued that memory is located in specific parts of the brain, and specific neurons can be recognized for their involvement in forming memories. The main parts of the brain involved with memory are the amygdala, the hippocampus, the cerebellum, and the prefrontal cortex 

4 0
2 years ago
Read 2 more answers
Is rust a pure substance or a mixture? <3
Naddik [55]
Iron is a pure substance
6 0
3 years ago
Read 2 more answers
Which of the following statements about the ordinary IR spectroscopic regions are TRUE? 1. In general, the IR FUNDAMENTAL region
yaroslaw [1]

Answer: the statements in 1 and 2 are true of IR spectroscopic region.

1. In general, the IR FUNDAMENTAL region has a longer wavelength region than the region we call the ultraviolet (uv) region.

2. We can sense some of the frequencies of the FUNDAMENTAL region of the IR as heat

Explanation:

IR has energy value between 10^-5eV - 10^-2eVwhile

UV has energy value of 4eV - 300eV

IR has low photon energy and cannot alter atoms and molecules while UV has sufficient energy to iodize atoms therefore UV has a higher energy band.

Infrared light falls just outside the visible spectrum, beyond the edge of what we can see as red.

5 0
3 years ago
What is the de Broglie wavelength, in cm, of a 11.0-g hummingbird flying at 1.20 x 10^2 mph?
KonstantinChe [14]

Answer:1.123 x 10^-31cm

Explanation:

mass of humming bird=  11.0g

speed= 1.20x10^2mph

but I mile = 1.6m

1km=1000

I mile = 1.6x10^3m

1.20x10^2mph= 1.6x10^3m /1mile x at 1.20 x 10^2

=1.932 x10^5m

recall that  

1 hr= 60 min

1 min=60 secs, 1hr=3600s

Speed = distance/ time

=1.932 x10^5 / 3600= 5.366 x 10 ^1 m/s

m= a 11.0g= 11.0 x 10^-3kg

h=6.626*10^-34 (kg*m^2)/s

Wavelength = h/mu

= 6.626*10^-34/(11 x 10^-3 x 5.366x 10^1)

6.63x10^-34/ 590.26x 10 ^-3= 1.123 x10^-33m

but 1m = 100cm

1.123 x 10 ^-33 x 100 = 1.123 x 10^-31cm

de broglie wavelength of humming bird = 1.123 x 10 ^-31cm

5 0
3 years ago
Other questions:
  • Is ethanol polar or nonpolar? Explain.
    10·1 answer
  • a r. tank contains H. initially at 100 kn/m2 and 20°C. 1 1/2 kg of H added so that t2 and p of the tank is 30°C and 250 kpa, Det
    13·1 answer
  • Apply the appropriate word to the definition indicated please! Not all words have to be used
    11·2 answers
  • What is the smallest chemical element?
    11·1 answer
  • You dissolve 4.5 mol of potassium hydroxide to make a 2 L solution. What is the molarity of the solution?
    15·1 answer
  • Which substance is oxidized and which is reduced in this reaction?
    14·1 answer
  • When a 1.0 M solution of HCl is titrated with a 1.0 M solution of KOH, which is the approximate pH at the equivalent point?
    11·1 answer
  • What particles flow through the circuit attached to a battery
    5·2 answers
  • Which statements describe the fossil record? Check all that apply.
    14·2 answers
  • 2. The enthalpy (heat) of hydration of a soluble ionic compound such, as KCl, is
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!