Question in Chemistry

Question

Compute the root-mean-square speed of Ar molecules in a sample of argon gas at a temperature of 61°C.

m s^-1

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Compute the root-mean-square speed of He molecules in a sample of helium gas at a temperature of 190°C.

m s^-1

Answer 1

The RMS (Root Mean Square( is a measure of the velocity of molecules of a gas)

the formula for RMS = square root (3)(R)(T)/molar mass of the gas in Kg

R the ideal gas constant is 8.31

Ar gas at 61 degrees celsius (334 K), its molar mass in Kg = 0.04

RMS Ar = square root (3)(8.31)(334)/0.04

RMS Ar = 456 m/s

He gas at 190 degrees celsius (463 K), molar mass in Kg = 0.004

RMS = square root (3)(8.31)(463)/0.004

RMS He gas = 1699 m/s