(a) (2) Restatement: Find partial pressure of each gas.
Ptotal= Pfluorine+ Pxenon
.
..
P nRTV
80 10
4 868 0 0821 273
mole K liters
moles liter atm K
flourine 1
xenon
::#
:: :::
= = =1.4 atm
.
..
P nRTV
80 10
4 0 0 0821 273
mole K liters
moles liter atm K
xenon 1
xenon
::#
:: :::
= = =1.1 atm
(b) Restatement: 23.00 g Li added to flask. Weight of LiF formed?
Xe is inert (no reaction with lithium).
The balanced equation for the reaction is thus F 2 (g) + 2Li(s) →2 LiF(s).
.
1. .Li
23 00
694
gLi (^1331)
gLi
mole Li= mole
Therefore, lithium is the limiting reagent. So 3.31 moles of Li is used up along with
3.31/2 or 1.66 moles of F 2. This leaves 3.21 moles (4.868 −1.66) of F 2.
..
331
2
2
1
25 94
860
moles Li
moles Li
moles LiF
mole LiF
g LiF
##= g LiF
(c) Restatement: Partial pressures of gases present after reaction, 0°C
Xenon is inert (no reaction): 1.1 atm pressure
.
..
P nRTV
80 10
3 21 0 0821 273
mole K liters
moles liter atm K
fluorine 1
fluorine::
::#
:::
== = 0.90 atm
Part II: Specific Topics