Empirical formula is the simplest ratio of components making up the compound. the molecular formula is the actual ratio of components making up the compound.
the empirical formula is CH₂. We can find the mass of CH₂ one empirical unit and have to then find the number of empirical units in the molecular formula.
Mass of one empirical unit - CH₂ - 12 g/mol x 1 + 1 g/mol x 2 = 12 = 14 g
Molar mass of the compound is - 252 .5 g/mol
number of empirical units = molar mass / mass of empirical unit
= 
= 18 units
Therefore molecular formula is - 18 times the empirical formula
molecular formula - CH₂ x 18 = C₁₈H₃₆
molecular formula is C₁₈H₃₆
The enthalpy change : -196.2 kJ/mol
<h3>Further explanation </h3>
The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)
The value of ° H ° can be calculated from the change in enthalpy of standard formation:
∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)
Reaction
2 H₂O₂(l)-→ 2 H₂O(l) + O₂(g)
∆H ° rxn = 2. ∆Hf ° H₂O - 2. ∆Hf °H₂O₂

Answer:
Kc =![\frac{[8.326x10-3]^{1} }{[1.113x10-2]^{1}[1.490x10-2]^{1} }](https://tex.z-dn.net/?f=%5Cfrac%7B%5B8.326x10-3%5D%5E%7B1%7D%20%7D%7B%5B1.113x10-2%5D%5E%7B1%7D%5B1.490x10-2%5D%5E%7B1%7D%20%20%7D)
Kc = 50.2059
Explanation:
1. Balance the equation
2. Use the Kc formula
Remember that pure substances, like H2 are not included on the Kc formula