I NEED HELP! This is a physical Chem question....I will provide you the variables n number. I dont get how i didnt get the answer.

1 mol of methane @ gas at 0 degree celsuis at 1atm. find the # of molecules whose speed is between 90m/s to 90.0002 m/s.

v = 90 m/s
dv = 0.0002 m/s
R= 8.314
T= 273
Na = 6.022*10^23
M = molar mass, which is 0.016kg/mol or (m*Na=16*6.022*10^23)
Plug into this equation
dNv = Na (M/2πRT) e^-((Mv^2)/2RT)

Question

I NEED HELP! This is a physical Chem question....I will provide you the variables n number. I dont get how i didnt get the answer.

1 mol of methane @ gas at 0 degree celsuis at 1atm. find the # of molecules whose speed is between 90m/s to 90.0002 m/s.

v = 90 m/s 
dv = 0.0002 m/s
R= 8.314
T= 273
Na = 6.022*10^23
M = molar mass, which is 0.016kg/mol or (m*Na=16*6.022*10^23)
Plug into this equation
dNv = Na (M/2πRT) e^-((Mv^2)/2RT)

ookawaiioo · Answer

The answer is 1.4*10^-7 molecules, but i dont know how to get that.... can someone how me.....