Answer: ΔH for the reaction is -277.4 kJ
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
![\Delta H=\sum [n\times \Delta H(products)]-\sum [n\times \Delta H(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%28products%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%28reactant%29%5D)
![\Delta H=[(n_{CCl_4}\times \Delta H_{CCl_4})+(n_{HCl}\times B.E_{HCl}) ]-[(n_{CH_4}\times \Delta H_{CH_4})+n_{Cl_2}\times \Delta H_{Cl_2}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%28n_%7BCCl_4%7D%5Ctimes%20%5CDelta%20H_%7BCCl_4%7D%29%2B%28n_%7BHCl%7D%5Ctimes%20B.E_%7BHCl%7D%29%20%5D-%5B%28n_%7BCH_4%7D%5Ctimes%20%5CDelta%20H_%7BCH_4%7D%29%2Bn_%7BCl_2%7D%5Ctimes%20%5CDelta%20H_%7BCl_2%7D%5D)
where,
n = number of moles
Now put all the given values in this expression, we get
![\Delta H=[(1\times -139)+(1\times -92.31) ]-[(1\times -74.87)+(1\times 121.0]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%281%5Ctimes%20-139%29%2B%281%5Ctimes%20-92.31%29%20%5D-%5B%281%5Ctimes%20-74.87%29%2B%281%5Ctimes%20121.0%5D)
Therefore, the enthalpy change for this reaction is, -277.4 kJ
74.62 g of magnesium oxide is formed from 45.00 g magnesium so 74.62-45.00= 29.62 g of oxygen is consumed or in other words a new compound is formed in the burning of magnesium in oxygen with a heavier mass than the pure magnesium.
Answer:
Option C. PV = nRT
Explanation:
The ideal gas gas equation gives the relationship between pressure, volume, number mole a gas and temperature of gas.
Mathematically, the ideal gas equation is given as:
PV = nRT
Where:
P is the pressure measured in atmosphere (atm).
V is the volume measured in litres(L) or cubic decimetre (dm³).
n is the number of mole of gas.
R is the gas constant (0.0821atm.L/Kmol)
T is temperature measured in Kelvin (K).
Catod(-)
K⁺
2H20 +2e⁻ ---> H2 +2OH⁻
We can also say, that
K⁺ +OH⁻ +H2 = KOH +H2
At the cathode KOH and H2 are formed.
The answer is (4) solid to gas. The entropy is the measurement of disorder. The entropy of CO2 under different status will increase from solid to liquid to gas. So the answer is (4).
