Question

A gas has density of 1.977 g dm-3 at STP.

(a) What is its molecular mass?

(b) What is its density at 77C and 0.95 atm pressure?

(c) If the gas in an oxide and has the formula XO2, what is the atomic mass of X?

Answer 1

first identify the molar mass and density relationship formula and the substitute the values in the equation and then calculate the values as follows

a) Mobara = DRT da density = 1.97791am? p=gas caustaut = 0,08314 bardm k mot 'T=213.15k Palbar MM=197770.08314 *23.15 MM = 44,897 siood Molarmess=144.99/mo b) doushi ty = MM XP 1. RT => 1944.90.962bar 0.08314 x 350115 density = 1,48 364 g/dm3] C) XO2 - Molemmers 544.9 O2 = Mos = 32 Xaton mass 244.9-32 7) 12.89 s/mol