Answer:
+4
Explanation:
The oxidation number of C in carbon dioxide (CO2) is (rules 1 & 2): 0 + (2 x 2) = +4 [Check (rule 3): +4 + 2(-2) = 0] The oxidation number of C in methane (CH4) is (rules 1 & 2): 0 – (4 x1) = -4 [Check (rule 3): -4 + 4(-1) = 0].
Answer:
Se requerirán 14.57 gramos de MgSO₄·7H₂O, que se disolverían en 105.43 gramos de agua.
Explanation:
Si tenemos 120 gramos de una solución al 10% de sulfato de magnesio en peso, habrán en la solución (120*10/100) 12 gramos de sulfato de magnesio (MgSO₄).
Sin embargo, el reactivo que está disponible es heptahidratado (MgSO₄·7H₂O), por lo que hay que calcular <em>cuántos gramos de sulfato de magnesio heptahidratado contendrán 12 gramos de MgSO₄</em>.
<u>Calculamos las moles de 12 gramos de MgSO₄</u>, usando su masa molecular:
- 12 g MgSO₄ ÷ 120.305 g/mol = 0.0997 mol MgSO₄.
<u>Después calculamos la masa de MgSO₄·7H₂O que contendrá 0.0997 mol MgSO₄</u>, usando la masa molecular de MgSO₄·7H₂O:
- 0.0997 mol * 246.305 g/mol = 14.57 g MgSO₄·7H₂O
Para saber la cantidad de agua en la que se disolverá el reactivo, restamos la masa de soluto de la masa total de la solución:
- 120 g - 14.57 g = 105.43 g
Where is the map??? Need the map to answer
Answer: The enthalpy of formation of 
is -396 kJ/mol
Explanation:
Calculating the enthalpy of formation of
The chemical equation for the combustion of propane follows:
The equation for the enthalpy change of the above reaction is:
![\Delta H^o_{rxn}=[(2\times \Delta H^o_f_{(SO_3(g))})]-[(2\times \Delta H^o_f_{(SO_2(g))})+(1\times \Delta H^o_f_{(O_2(g))})]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28SO_3%28g%29%29%7D%29%5D-%5B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28SO_2%28g%29%29%7D%29%2B%281%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28O_2%28g%29%29%7D%29%5D)
We are given:
Putting values in above equation, we get:
![-198=[(2\times \Delta H^o_f_{(SO_3(g))})]-[(2\times \Delta -297)+(1\times (0))]\\\\\Delta H^o_f_{(SO_3(g))}=-396kJ/mol](https://tex.z-dn.net/?f=-198%3D%5B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28SO_3%28g%29%29%7D%29%5D-%5B%282%5Ctimes%20%5CDelta%20-297%29%2B%281%5Ctimes%20%280%29%29%5D%5C%5C%5C%5C%5CDelta%20H%5Eo_f_%7B%28SO_3%28g%29%29%7D%3D-396kJ%2Fmol)
The enthalpy of formation of is -396 kJ/mol
