The amount of heat involved in the synthesis of 1 mole of a compound from its elements with all substances in their standard states at 25 degrees celcius is called

Answer : It is called as standard heat of formation.

Explanation :

Enthalpy of formation : The enthalpy of change when one mole of a pure compound is formed from its elements is called the enthalpy of formation. It is denoted as, .

Standard heat of formation : When the reacting elements and the product formed are all in their standard state at , the enthalpy change accompanying the chemical reaction is called the standard enthalpy of formation or standard heat of formation. It is denoted as, .

Hence, it is called as standard heat of formation.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

the dependant variable is spilled water

the independent is the heat