The surface tension of water is 7.28 ✕ 10−2 J/m2 at 20°C. Predict whether the surface tension of heptane would be higher or lowe
r than that of water at the same temperature. Explain your answer.
1 answer:
Answer:
Lower
Explanation:
Surface tension occurs because molecules at the surface do not have molecules above them, so they cohere more strongly to their neighbours.
The stronger cohesive forces make it more difficult to move an object through the surface than when it is beneath the surface.
The attractive forces in water are strong because of hydrogen bonding.
A hexane molecule is nonpolar, so the only attractions are the weak London dispersion forces.
The cohesive forces at the surface are much lower than those in water, so the surface tension of hexane is lower than that of water at the sane temperature.
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Answer:
Paper chromatography is a basic technique of chromatography. It consist in the separation of the mixe components using a solvent.
Explanation:
Paper chromatography is a basic technique of chromatography. It consists in the separation of the mixed components using a solvent.
Paper chromatography consists of put some dot of the mix using a glass capillary into a specialized paper, generally made of cellulose, this is called a stationary phase.
Then you put this paper into a camera of glass named, chromatography camera, where previously contain a solvent. The solvent also know as a mobile phase, the type can be defined before the test and involves a study of the kind of the mix, and the compound you want to separate.
The chromatography camera has to be closed all the time during the test, and you can't move at all because the movement of the solvent can alternate the result.
Very often, the solution of the solvent is a mix of different liquid substances with different polarities.
When the stationary phase put into the camera, the solvent starts to move up over the paper, until the separation of the compounds is observable.
the Rf is a value who relates the move of the mobile phase with the move of the distance traveled by the substance tested.
To undersant the paper chromatography, you can watch the images attached.
The first is an image of the chromatography camera.
The second one is an image of a cellulose paper after the chromatography is done. You can watch the dots who indicates the traveling of the compound across the paper.
The third one can show you the evolutions of paper chromatography, from the beginning to the end.
To calculate the Rf value you have to use the equation:
Rf = distance traveled by the substance/distance traveled by the solvent/
<u>Rf = 52mm/81mm =0.64</u>
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At temperature, a sample of neon gas will occupy
volume.
Further Explanation:
The given problem is based on the concept of Charles’ law. Charles’ law states that “at constant pressure and fixed mass the volume occupied an ideal gas is directly proportional to the Kelvin temperature.”
Mathematically the law can be expressed as,
Or,
Here, <em>V</em> is the volume of the gas, <em>T</em> is Kelvin temperature, and <em>k</em> is proportionality constant.
Given information:
The initial volume of neon gas is .
The final volume of neon gas is .
The initial temperature value is .
To calculate:
The final temperature
Given Condition:
- The pressure is constant.
- Mass of gas is fixed.
Solution:
Step 1: Modify the mathematical expression for Charles’ law for two different temperature and volume values as follows:
Here,
is the initial volume of the gas.
is the final volume of the gas.
is the initial temperature of the gas.
is the final temperature of the gas.
Step 2: Rearrange equation (2) for .
…… (2)
Step 3: Convert the given temperature from degree Celsius to Kelvin.
The conversion factor to convert degree Celsius to Kelvin is,
…… (3)
Substitute for
in equation (3) to convert temperature from degree Celsius to Kelvin.
Step 4: Substitute for
,
for
and
for
in equation (2) and calculate the value of
.
Important note:
- The temperature must be in Kelvin.
- The condition of fixed mass and fixed pressure must be fulfilled in order to apply Charles’ law.
Learn More:
1. Gas laws brainly.com/question/1403211
2. Application of Charles’ law brainly.com/question/7434588
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: States of matter
Keywords: neon, volume, occupies, temperature, Kelvin, degree Celsius, Charle’s law, constant pressure, fixed mass, 40.81 m^3 , 50.00 m^3 , 23.5 degree C , celsius , 363 K , sates of matter, initial volume, final volume, initial temperature, final temperature, V1 , V2 , T1 , T2 .
