Consider the reaction 2al(oh)3(s)→al2o3(s)+3h2o(l) with enthalpy of reaction δhrxn∘=21.0kj/mol what is the enthalpy of formation of al2o3(s)?

The enthalpy of the formation of is coming out to be -399.5 kJ/mol.

Explanation:

Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as

The equation used to calculate enthalpy change is of a reaction is:  

For the given chemical reaction:

The equation for the enthalpy change of the above reaction is:

We are given:

Putting values in above equation, we get:

Hence, the enthalpy of the formation of is coming out to be -399.5 kJ/mol.

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l