Explain the difference between physical equilibrium and chemical equilibrium. Give two examples of each.

Explanation:

In a chemical equilibrium, there are different reactants and products are involved. For example, reaction equation for self-ionization is as follows.

This reaction is a chemical equilibrium. Also, nitrogen dioxide when present in equilibrium with nitrogen tetraoxide represents chemical equilibrium.

On the other hand, in a physical equilibrium same substance is present in different physical states. For example, when ice is present in equilibrium with water then it shows physical equilibrium.

And, liquid water present in equilibrium with water vapor also represents physical equilibrium.

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