The two of them both made models of the current atom, which was very excellent because now we could imagine how an atom would look. I would say that the best one was the electron orbital configuration because we needed to know what valence electrons are.
I think the first blank is "solidity" and second is "object."
Answer:
18
Explanation:
Sabemos que la fórmula química del agua es H2O.
Usando la información que; H = 1, O = 16, podemos calcular la masa molar del agua de la siguiente manera
[2 (1) + 16] = 18
Por tanto, la masa molar del agua es 18
The combustion of naphthalene is given as:
C10H8 (s) + 12 O2 (g) --> 10CO2 (g) + 4 H2O (l)
Enthalpy of combustion ΔH = -5157 kJ/mol
Now, the enthalpy change of a reaction is given
ΔH = ∑nΔHf (products) - ∑nΔHf (reactants)
where n = number of moles
ΔHf = enthalpy of formation
Therefore,
ΔH = [10*ΔHf(CO2) + 4*ΔHf(H2O)] - [1*ΔHf(C10H8) + 12*O2]
-5157 = [10*(-393.5) + 4*(285.83)] - [ΔHf(C10H8) + 12*(0)]
ΔHf(C10H8) = 78.68 kJ/mol
