Question

A dragon accidently swallows a sip of water, H2O(1). When the sip of water enters the dragons stomach which is at 125C (considerably hotter than our human stomachs) it instantly becomes and fills the volume of the dragons stomach which is 112L. How many moles of water did the dragon swallow? Since the dragon is on the ground when he drinks the water the pressure inside stomach is 1.0atm.

Answer 1

• P=1atm
• V=112L
• T=125°C=398K

Now

Ideal gas equation

$\\ \rm\Rrightarrow PV=nRT$

$\\ \rm\Rrightarrow 112=n(8.314)(398)$

$\\ \rm\Rrightarrow n=0.033mol$

Answer 2

Answer:

$0.03384\ mol$

Explanation:

Step 1:  Determine important information

Ideal gas law → $PV=nRT$

At the end of the problem statement we can see that the pressure is $1.0\ atm$.  V is the volume which is given as $112\ L$.  n is the amount of substance which is what we are trying to find.  R is the ideal gas constant is the same for every problem which is $8.3145\ J * mol^{-1}*K^{-1}$.  Finally, T is the temperature which is given as $125\ C$ but we have to convert to kelvins which we get $398\ K$.

Step 2:  Plug in the information and solve

$PV=nRT$

$(1.0\ atm)*(112\ L) = n*(8.3145\ J * mol^{-1}*K^{-1})*(398\ K)$

$112=n*(3,309.171)$

$\frac{112}{(3,309.171)}=\frac{n*(3,309.171)}{(3,309.171)}$

$0.03385\ mol = n$

Answer: $0.03384\ mol$