Answer to Question #145865 in General Chemistry for Erica

Question

The average speed of nitrogen gas molecular at 25 degree celsius is 515 m/s. (a) what is the average speed of a He molecules at 25 degree celsius. (b) a CO2 gas atom at 25 degree celsius.

Answer 1

ACCORDING TO :

average speed of nitrogen gas molecular at 25 degree celsius is 515 m/s. 

we know the V_rms of N₂ is 515 m/s.

Now we calculate the V_rms for He₂ and CO₂

Now we calculate V_rms of He₂

V_rms = $\sqrt\frac{3RT}{M}$ R= 8.314J⋅K−1⋅mol−1.

and T = 273 + 25⁰C = 298K

Mass of He₂ = 8.0052 × $10^-³$

V_rms = $\sqrt\frac{3×8.314×298}{8.0052×(10)^-³}$

V_rms = 963.57 m/s

This is the average speed of He molecule is 963.57 m/s.

Now we calculate V_rms ofCO₂

V_rms =$\sqrt\frac{3RT}{M}$ R =8.314J⋅K−1⋅mol−1.

and T = 273 + 25⁰C = 298K

Mass of CO₂ = 44.01 × $10^-³$

V_rms = $\sqrt\frac{3×8.314×298}{44.01×10^-³}$

V_rms = 410.95 m/s

This is the average speed of CO₂ atom is 410.95 m/s.