Question #16856

2 Answers
Apr 14, 2017

Answer:

3.61

Explanation:

its quite simple if you go by a simple method of finding density at STP
we got
#"Density"=("Mass")/("Volume")#
we know that mas of #HBr# is 81 units
and one mole of #HBr# weighs 81 #gm#
and we also know that the volume of one mole of any gas is 22.4 #L#hence , we have got our data .
upon substitution with the formal equation of density we get .
#d=81/22.4=3.61g m^(-3)#

Apr 14, 2017

Answer:

The density of #"HBr"# at STP is 3.563 g/L.

Explanation:

Yes, there is a gas law equation for density.

It is a variation of the Ideal Gas Law.

#color(blue)(|bar(ul(color(white)(a/a)pV = nRTcolor(white)(a/a)|)))" "#

Since

#n = "mass"/"molar mass" = m/M#,

we can write

#pV = m/MRT#

or

#p = (m/V)(RT)/M#

And density #ρ = m/V#,

so

#p = ρ(RT)/M#

This gives

#ρ = (pM)/(RT)#

STP is defined as 1 bar and 0 °C.

In this problem,

#p color(white)(ll)= "1 bar"#
#M = "80.91 g·mol"^"-1"#
#Rcolor(white)(l) = "0.083 14 bar·L·K"^"-1""mol"^"-1"#
#T color(white)(l)= "273.15 K"#

#ρ = (1 color(red)(cancel(color(black)("bar"))) × 80.91 "g"·color(red)(cancel(color(black)("mol"^"-1"))))/("0.083 14" color(red)(cancel(color(black)("bar")))·"L"·color(red)(cancel(color(black)("K"^"-1""mol"^"-1"))) × 273.15 color(red)(cancel(color(black)("K")))) = "3.563 g/L"#