Discover the answers you need at Westonci.ca, where experts provide clear and concise information on various topics. Connect with professionals on our platform to receive accurate answers to your questions quickly and efficiently. Our platform offers a seamless experience for finding reliable answers from a network of knowledgeable professionals.

The latent heat of vaporization for water at room temperature is 2430 J/g.

1. How much kinetic energy does each water molecule that evaporates possess before it evaporates?
2. Find the pre-evaporation rms speed of a water molecule that is evaporating.
3. What is the effective temperature of these molecules (modeled as if they were already in a thin gas)?

4. Why do these molecules not burn you

a. These molecules got to be slow-moving in collisions that made other molecules fast-moving; the average molecular energy decreases.
b. These molecules got to be slow-moving in collisions that made other molecules fast-moving; the average molecular energy is unaffected.
c. These molecules got to be fast-moving in collisions that made other molecules slow-moving; the average molecular energy is unaffected.
d. These molecules got to be fast-moving in collisions that made other molecules slow-moving; the average molecular energy increases.



Sagot :

Answer:

1)   [tex]kinectic energy=7.26*10^-^2^0J[/tex]

2)  [tex]V= 2.0m/s[/tex]

3)  [tex]T=3.5*10^3K[/tex]

4)  The Molecules do not burn because of the presences of hydrogen bond in place

Explanation:

From the question we are told that

latent heat of vaporization for water at room temperature is 2430 J/g.

1)Generally in determining the molar mass of water evaporated we have that

-One mole (6.02 x 10. 23 molecules)

-Molar mass of water is 18.02 g/mol

Mathematically the mass of water is give as

   

  [tex]M=\frac{18.02}{6.02*10^-^2^6}[/tex]

  [tex]M=3*10^-^2^3g[/tex]

Therefore

  [tex]kinectic energy=2430J/g*3*10^-^2^3g[/tex]

 [tex]kinectic energy=7.26*10^-^2^0J[/tex]

b)Generally the evaporation speed V is given as[tex]V= \sqrt{\frac{K.E*2}{m} }[/tex]

Mathematically derived from the equation

[tex]\frac{1}{2} mv^2 =K.E[/tex]

To Give

[tex]V= \sqrt{\frac{K.E*2}{m} }[/tex]

[tex]V= \sqrt{\frac{7.26*10^-^2^0J*2}{3*10^-^2^3g} }[/tex]

[tex]V= 2.0m/s[/tex]

c)Generally the equation for velocity   [tex]Vrms=\sqrt{\frac{3RT}{M} }[/tex]

Therefore

Effective temperature T is given by

      [tex]T=\frac{\sqrt{v}*m}{R}[/tex]

where

     [tex]T=\frac{\sqrt{2.0m/s}*6.02*10^-^2^6}{0.082057 L atm mol-1K-1}[/tex]

     [tex]T=3.5*10^3K[/tex]

4) The Molecules do not burn because of the presences of hydrogen bond in place