2CH4(g)⟶C2H4(g)+2H2(g)
1 answer:
Answer: The enthalpy change for the reaction is, 201.9 kJ
Explanation:
Based on Hess’s law of constant heat summation, the energy released or absorbed in a chemical reaction stays constant, regardless of whether the process unfolds in one step or multiple steps.
This principle implies, that chemical equations can be treated analogously to algebraic expressions, allowing addition or subtraction to create the needed equation. Thus, the overall enthalpy change corresponds to the summation of the individual enthalpy changes of the reactions occurring in between.
The balanced equation for appears as follows,
The intermediate balanced reactions are outlined as follows,
(1)
(2)
(3)
(4)
Next, we will multiply the first reaction by 2, reverse the second, and reverse and halve the third and fourth reactions before combining them. This gives us:
(1)
(2)
(3)
(4)
Therefore, the expression for the enthalpy of the reaction is,
Hence, the enthalpy change for this reaction is, 201.9 kJ
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Answer:
La masa molar del compuesto es: 168.82 g/mol
La masa molar del gas es: 16.38 g/mol
Explanation:
(a)
Utilizando la ecuación de gases ideales:
donde,
P es la presión
V es el volumen
n es el número de moles
T es la temperatura
R es la constante de los gases, cuyo valor es = 0.0821 L.atm/K.mol
Además,
Moles = masa (m) / Masa molar (M)
La densidad (d) = Masa (m) / Volumen (V)
Así, la ecuación de gases ideales se puede expresar como:
Dado que:-
Presión = 20 kPa = 20000 Pa
La expresión para la conversión de presión en Pascal a presión en atm se muestra a continuación:
P (Pa) = P (atm)
20000 Pa = atm
Presión = 0.1974 atm
Temperatura = 330 K
d = 1.23 kg/m³ = 1.23 g/L
Masa molar =?
Aplica la fórmula:
0.1974 atm × M = 1.23 g/L × 0.0821 L.atm/K.mol × 330 K
⇒M = 168.82 g/mol
La masa molar del compuesto es: 168.82 g/mol
(b)
Dado que:
Presión = 152 Torr
Temperatura = 298 K
Volumen = 250 cm³ = 0.25 L
Utilizando la ecuación de gases ideales:
R =
Aplicando la fórmula:
152 Torr × 0.25 L = n × 62.3637 L.torr/K.mol × 298 K
⇒n = 0.002045 moles
Dado que:
Masa del gas = 33.5 mg = 0.0335 g
Masa molar =?
La fórmula para calcular los moles se muestra a continuación:
Así,
La masa molar del gas es: 16.38 g/mol
Answer:
Explanation:
The percent composition indicates the mass percentage of a specific element within the compound.
The chemical formula for chromium(III) nitrate is .
The molar mass for chromium(III) nitrate is calculated at 238.011 g/mol.
Each mole of chromium(III) nitrate includes 9 moles of oxygen.
The molar mass of oxygen is 16 g/mol.
Hence, Mass = Molar mass * Moles = 16 * 9 g = 144 g.