Question

#1) Which of the following gas samples contains the greatest mass of gas molecules?

a. 1 L of He at STP

b. 1 L of Xe at STP

c. 1 L of H₂ at STP

d. All are the same

#2) Which physical property/state is incorrectly matched?

a. liquids - rigid shape

b. gases - easily compressed

c. gases and liquids - flow

d. solids - higher density than gases

e. liquids - incompressible

Answer 1

1.

At STP ; Equal volumes of gases will have equal moles

so all have the same moles

Then mass of gas = moles * Molar mass

so the gas which has greater molar mass will have greater mass

Xe has greater molat mass

so b. 1 L of Xe at STP will have greatest mass

2. The incorrect statement is  

a. liquids - rigid shape

since liquid gets the shape of the vessel .

there should be no rigid shape for liquids