<span>Water:
*can dissolve most substances
* contains dissolved minerals
*expands when it freezes</span>
Answer:
Increasing temperature
Explanation:

Enthalpy of the reaction = -393.5 kJ/mol
Negative sign implies that reaction is exothermic.
Effect of change in reaction condition is explained by Le chateliers principle.
According to Le chateliers principle, if the reaction conditions of a reversible reaction in a state of dynamic equilibirum is changed, the reaction will move in a direction to counteract the change.
1. Increasing the temperature
Forward reaction is exothermic that means temperature increases in forward direction. Backward reaction will be endothermic and so there is decrease in temperature in backward direction or in left direction.
On increasing temperature, reaction will be move in direction to counteract the increased temperature, therefore reaction will move in left direction.
2. Adding O2
If O2 is added, then reaction will move in a direction in which its get consumed. So, reaction will move in forward direction or in right direction.
3. Removing C (s)
Le Chatelier's principle does not apply on solids, so removal of C(s) does not affect the equilibrium.
Answer:
pH of the solution = 9.45
Explanation:
pKb = 8.57
pKb = -logKb
Kb = antilog pkb

ICE table for the ionization of pyrodine is:

initial 0.435 0 0
equi. 0.435 - x x x
so,
![k_b =\frac{ [C_5H_5NH^+][OH^-]}{[C_5H_5N]}\\1.78\times 10^{-9}=\frac{x^2}{0.453 - x}](https://tex.z-dn.net/?f=k_b%20%3D%5Cfrac%7B%20%5BC_5H_5NH%5E%2B%5D%5BOH%5E-%5D%7D%7B%5BC_5H_5N%5D%7D%5C%5C1.78%5Ctimes%2010%5E%7B-9%7D%3D%5Cfrac%7Bx%5E2%7D%7B0.453%20-%20x%7D)
As kb is very less that means there is very less ionization, hence x can be ignored as compared to 0.435

pOH = -log[OH-]
![pOH = -log[2.78\times 10^{-5}]\\=4.55](https://tex.z-dn.net/?f=pOH%20%3D%20-log%5B2.78%5Ctimes%2010%5E%7B-5%7D%5D%5C%5C%3D4.55)
pH = 14 - pOH
= 14 - 4.55
= 9.45