$($b$)$ What is the difference between a triple point and a critical point on a phase diagram?

$(10$ marks$)$

$($i$)$ Draw the phase diagram above and label with an arrow to represent all process that occur in the diagram. Identify each of the process either endothermic or exothermic reaction.

$($ii$)$ Describe all the process that occur in the following path $(1234).$

$(10$ marks$)$