Carbonic acid is a weak acid, so it will release H+ ions into
the solution. When the concentration of H+ increases, the pH
decreases.
- C Entropy is the measure of a system’s randomness, and gases are more
random than liquids. Also, the more molecules, the greater the
randomness. In choice (C), a liquid is converted into two gases, and the
number of molecules is increasing, so entropy must be increasing.
- A As pressure is decreased at constant temperature, phase changes could
occur as shown in the diagram below:
