Answer:
B. what happens when iron rusts in the presence of water
Explanation:
Chemistry is a branch of science involving the composition and changes of matter. In other words, a chemist, who is a trained specialist in the science of chemistry, seeks to answer questions related to properties of matter.
In this question, a chemist is most likely to study "what happens when iron rusts in the presence of water" because it involves a change in the chemical properties of a substance (iron) i.e. a chemical change. However, what happens when ice melts to liquid water is a physical change.
Start with the ideal gas equation, <span><span><span>PV=nRT</span> </span><span>PV=nRT</span></span>
and rearrange for pressure to get <span><span><span>p=<span><span>nRT</span>V </span></span> </span><span>p=<span><span>nRT</span>V</span></span></span>
. You have all the necessary variables in their proper units, so plug em' into the equation to solve for pressure in units of atmospheres.
<span><span><span>P=<span><span>(2.5 mol)(300 K)(0.08206 L atm <span><span>K </span><span><span>−1</span> </span></span> mo<span><span>l </span><span><span>−1</span> </span></span></span><span>50.0 L</span> </span>=1.23 atm</span> </span><span>P=<span><span>(2.5 mol)(300 K)(0.08206 L atm <span>K<span>−1</span></span> mo<span>l<span>−1</span></span></span><span>50.0 L</span></span>=1.23 atm</span></span>
All that needs to be done now is converting atmospheres to mm <span><span><span>Hg</span> </span><span>Hg</span></span>
.
<span><span><span>1.23 atm∗<span><span>760 mm Hg</span><span>1 atm</span> </span>=935 mm Hg</span> </span><span>1.23 atm∗<span><span>760 mm Hg</span><span>1 atm</span></span>=935 mm Hg</span></span>
.
That value makes sense, since the original pressure in atmospheres was above 1, the pressure in mm <span><span><span>Hg</span> </span><span>Hg</span></span>
will be above 760.
The answer is the trachea
