<p>58.</p>
<p>Increased randomness results under which of the following conditions?</p>
<p>I. A 1L sample of He(g) and 1L sample of Ne(g) are mixed in a 2L flask.
II. Ice melts.
III. CaO(s) reacts with CO2(g) to form CaCO3(s)</p>
<p>A. I
B. II
C. I and II
D. II and III
E. I, II, III</p>
<p>II) When ice melts it goes from (s) -> (l), so entropy increases.
III) (s) + (g) -> (s); so entropy decreases.
I) He(g) + Ne(g) -> He(g) + Ne(g); so entropy doesn't change</p>
<p>Therefore I chose (B), but the correct answer is [C]</p>
<p>Someone explain!!</p>
<p>(C) is indeed correct. My reasoning is that I is true because during mixing, more volume must become available to each gas. The particles of the gas do not interact and that along with the extra volume causes increased randomness or entropy. II is true because in order for ice to melt, heat must be added. An increase in temperature will result in greater disorder between particles, as you are going from a solid to a liquid. III is false because if you are going from a gas and solid to just a solid, the particles of gas will be more tightly packed than before the reaction, so there will be less entropy. Thus, I and II are true and III is false -> (C)</p>