Question

what pressure will be required for neon at 30.0C to have the same density as nitrogen at 20.0C and at 1.00 atm? state your final answers in atm unit using 3 SF's

Answer 1

Density of Nitrogen at 20.0 C = m/V = P_N2M_N2/RT_N2

[ P_N2=pressure of nitrogen, M_N2= molar mass of nitrogen, R=Universal const, T_N2= temperature of nitrogen]

= (1 atm x 28 g mol^-1)/ ( 0.082 L atm K^-1 mol^-1 x 293.15 K)

= 1.16 g L^-1

Similarly we can write, density of Neon = P_NeM_Ne/RT_Ne here terms have usual meanings (molar mas =20 g mol^-1)

We know density is 1.16 g/L ,    1.16 g/L = (P_Ne x 20 g mol^-1) / (0.082 L atm K^-1 mol^-1 x 303.15 K)

P_Ne = 1.44 atm

This should be the pressure at which density will be same.