Question

1) 1.75g of an unknown gas at 31°C and 1.05 atm is stores in a 2.55-L flask.

- What is the density of the gas?

______ g/L

- What is the molar mass of the gas?

_____ g/mol

2) If the absolute temperature of a gas is tripled, what happens to the root- mean- square speed of the molecules? (nothing,the new rms speed is 9 times the original rms speed, the new rms speed is 3 times the original rms speed, the new rms speed is 1.732 times the original rms speed, the new rms speed is 1/3 the orginal rms speed)

3) Calculate the average translational kinetic energy (sometimes just called average kinetic energy)...

- for one mole of gas at 723 K.

Ek= ________ J/mol

- for a single gas molecule at 723 K

Ek= ________ J/molecule

4) If He(g) has an average kinetic ebergy of 8890 J/mol inder certain conditions, what is the root mean square speed of F2(g) molecules under the same conditions?

- ___________ m/s

5) Use the van der Waals equation os state to calculate the pressure of 2.70 mol of H2O at 477 K in a 5.10-L vessel.

- P= _________ atm

- use the ideal gas equation to calculate the oressure under the same conditions.

P= _______ atm