Question 2: Phase Changes (14 points) a. Rewrite each of the following equations for phase changes, to include the heat required
1 answer:
Explanation:
(i) The equilibrium reaction equation will be as follows.
A reaction in which there will be absorption of heat energy is known as endothermic reaction.
A reaction in which there will be release of heat energy is known as exothermic reaction.
As liquid state of water is changing into solid state. So, it means that molecules of water came close to each other. Hence, there will be release of heat this means that reaction is exothermic in nature.
Hence, phase change from liquid to solid will be exothermic in nature.
Latent heat of fusion is defined as the amount of energy necessary to convert 1 gram of a solid into liquid state at its melting point.
So, when solid state of water changes into liquid state then it means energy is absorbed by the molecules of ice due to which they have gained kinetic energy. Hence, they moved away from each other leading to formation of liquid state of water.
Latent heat of freezing of liquid water is 334 J/g.
Specific heat of liquid water is 4.186
Specific heat of steam is 1.996
Specific heat of ice is 2.1
(ii) The equilibrium reaction equation will be as follows.
As liquid state of water is changing into gaseous or vapor state. So, it means molecules of liquid water has gained kinetic energy hence, they colloid more rapidly with each other.
As a result, heat will be absorbed by the liquid state of water. Hence, heat will be absorbed. Therefore, phase change from liquid to gas will be endothermic in nature.
Whereas when gaseous state of water will change into liquid state then heat will be released during this process of condensation. As a result, in that case reaction will be exothermic in nature.
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Answer:
Δ
Δ
Explanation:
Hello,
At the first state, the molar volume is:
The volume in both the second and third state:
Now, as it is about an adiabatic process, one remembers the following relationships:
- Next, for the aforesaid volumes and the first pressure, one computes the second pressure as:
- And the temperature:
- Q:
It is clear that the heat for the first process is 0 as it is adiabatic, but for the second one, it is computed as:
Then the total heat:
- The work for the first process is:
It is clear that the second process is isochoric, so the work here is zero, thus, the total work is:
- For the two processes, ΔU becomes the same value since the system returns to the initial temperature, so ΔU total is 0, thus, for each process, one's got:
- Finally, the total enthapy is also 0 due to same aforesaid reason, thus, each enthalpy is:
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Answer:
2667 tires are needed to meet the demand of ten homes for one year.
Explanation:
According to the Second Law of Thermodynamics, only a part of generated energy when tires are burned can be utilized due to irreversibilities associated with finite temperature differences. The energy from a tire that can be transformed into electricity (), measured in kilowatt-hours, is estimated by definition of efficiency:
Where:
- Efficiency, dimensionless.
- Energy liberated by burning, measured in kilowatt-hours.
Given that and
, the amount of energy per year generated by a tire is:
Now, the amount of tires needed to meet the demand of then homes for one year is:
2667 tires are needed to meet the demand of ten homes for one year.
Answer:
The synthesis of p-chlorobenzenesulfonic acid with the reagents for each step and the structure of the monosubstituted intermediate compound is shown in the drawing below.
Explanation:
Benzenesulfonic acid is obtained from the sulfonation of benzene, using concentrated smoking sulfuric acid.
Chlorination of benzenesulfonic acid with chlorine without catalyst requires a polar solvent, such as acetic acid to obtain the selectivity in the position for and the ortho derivative in a low proportion.
