How many triple points are in the phase diagram below:

There are 3 triple points in the given phase diagram.

Explanation: Triple point is defined as the point at which the temperature and pressure of the 3 phases are in equilibrium with each other.

In the given phase diagram, there are three points which is satisfying this definition.

Point A: At this point The monoclinic form and rhombic form have the same vapor pressure. Hence,

Point B: At this point, the monoclinic form starts to melt. Hence,

Point C: At this point, the rhombic form, monolinic form and liquid is in equilibrium. Hence,

Hence, this system has 3 triple points.

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol