Answer:
C. ΔG is positive at low temperatures, but negative at high temperatures (and zero at some temperature).
Explanation:
Since we need to give energy in the form of heat to vaporize a liquid, the enthalpy is positive. In a gas, molecules are more separated than in a liquid, therefore the entropy is positive as well.
Considering the Gibbs free energy equation:
ΔG= ΔH - TΔS
+ +
When both the enthalpy and entropy are positive, the reaction proceeds spontaneously (ΔG is negative) at high temperatures. At low temperatures, the reaction is spontaneous in the reverse direction (ΔG is positive).
Answer:
A.It is the same for every sample of a single substance.
Explanation:
The answer is (2). If you recall Rutherford's gold foil experiment, remember that a stream of positively charged alpha particles were shot at a gold foil in the center of a detector ring. The important observation was that although most of the particles passed straight through the foil without being deflected, a tiny fraction of the alpha particles were deflected off the axis of the shot, and some were even deflected almost back to the point from which they were shot. The fact that some of the alpha particles were deflected indicated a positive charge (because same charges repel), and the fact that only a small fraction of the particles were deflected indicated that the positive charge was concentrated in a small area, probably residing at the center of the atom.
Chlorine gas reacts to potassium bromide to form potassium chloride in solution and liquid bromine.
I hope this helps/answers your question! I vaguely remember getting this question before too
Use the formula for second order reaction:

C = concentration at time t
C0 = initial conc.
k = rate constant
t = time
1st equation :

2nd Equation:

Find

from 1st equation and put it in 2nd equation:


k = 0.046