It went under a physical change because it (1) changed color. (2) changed form.
Since the volume is constant,
p1/t = p2/ t
210/120 = p2/150
p2= 262.5kpa
CL- is Chloride, so your answer would be C.Chloride.
Answer : The correct option is, 7.58
Explanation : Given,
pOH = 6.42
pH : It is defined as the negative logarithm of the hydrogen ion concentration.
As we know that,

Now put the value of pOH in this expression, we get the pH of this solution.




Therefore, the pH of this solution is, 7.58