Question

question 5 1 pts
a vessel containing the following gases is analyzed by a scientist:
he, ne, ar, kr
which of the following gases would be moving the slowest?
○ kr
○ he
○ ar
○ ne

question 6 1 pts
if we quadruple the energy in a vessel of gas, what happens to the velocity of the gas particles?
○ the velocity halves.
○ the velocity doubles.
○ the velocity quadruples.
○ the velocity stays the same.

Explanation:

Step1: Relate speed to molar mass

Graham's Law: $v \propto \frac{1}{\sqrt{M}}$, where $v$ = particle speed, $M$ = molar mass. Higher $M$ = slower speed.
Molar masses: He=4 g/mol, Ne=20 g/mol, Ar=40 g/mol, Kr=84 g/mol. Kr has highest $M$.

Step2: Relate energy to velocity

Kinetic energy: $KE = \frac{1}{2}mv^2$. Rearranged: $v = \sqrt{\frac{2KE}{m}}$. If $KE$ becomes $4KE$, new $v' = \sqrt{\frac{2(4KE)}{m}} = 2\sqrt{\frac{2KE}{m}} = 2v$.

Answer:

Question 5: Kr
Question 6: The velocity doubles.