Enthalpy of formation is calculated by subtracting the total enthalpy of formation of the reactants from those of the products. This is called the HESS' LAW.
ΔHrxn = ΔH(products) - ΔH(reactants)
Since the enthalpies are not listed in this item, from reliable sources, the obtained enthalpies of formation are written below.
ΔH(C2H5OH) = -276 kJ/mol
ΔH(O2) = 0 (because O2 is a pure substance)
ΔH(CO2) = -393.5 kJ/mol
ΔH(H2O) = -285.5 kJ/mol
Using the equation above,
ΔHrxn = (2)(-393.5 kJ/mol) + (3)(-285.5 kJ/mol) - (-276 kJ/mol)
ΔHrxn = -1367.5 kJ/mol
<em>Answer: -1367.5 kJ/mol</em>
Answer:
True
Explanation:
magnesium and copper react with dilute acids to make salts and hydrogen gas
The mole fraction of cation (Al)=0.4
<h3>Further explanation</h3>
Given
1 M of Aluminium sulphate
Required
The mole fraction of cation
Solution
Ionization of the Aluminum sulfate solution( assume 1 L solution ) :
mol Al₂(SO₄)₃ = M x V = 1 M x 1 L = 1 mol
Al₂(SO₄)₃⇒2Al³⁺ + 3SO₄²⁻
1 mol 2 mol 3 mol
From this equation, total mol in solution = 2+3 = 5 moles
Mol fraction Al(as a cation) :
= 2/5=0.4
