Answer:
D
Explanation:
There are 2 oxygens on the reactants side (OH)2 but 4 on the products side (2H2O). You cannot get 2 oxygens out of nowhere, so it is not balanced.
Answer : The entropy change of reaction for 1.62 moles of 
reacts at standard condition is 217.68 J/K
Explanation :
The given balanced reaction is,
The expression used for entropy change of reaction 
is:
![\Delta S^o=[n_{Br_2}\times \Delta S_f^0_{(Br_2)}+n_{F_2}\times \Delta S_f^0_{(F_2)}]-[n_{BrF_3}\times \Delta S_f^0_{(BrF_3)}]](https://tex.z-dn.net/?f=%5CDelta%20S%5Eo%3D%5Bn_%7BBr_2%7D%5Ctimes%20%5CDelta%20S_f%5E0_%7B%28Br_2%29%7D%2Bn_%7BF_2%7D%5Ctimes%20%5CDelta%20S_f%5E0_%7B%28F_2%29%7D%5D-%5Bn_%7BBrF_3%7D%5Ctimes%20%5CDelta%20S_f%5E0_%7B%28BrF_3%29%7D%5D)
where,
= entropy change of reaction = ?
n = number of moles
= standard entropy of formation
= 245.463 J/mol.K
= 202.78 J/mol.K
= 292.53 J/mol.K
Now put all the given values in this expression, we get:
![\Delta S^o=[1mole\times (245.463J/K.mole)+3mole\times (202.78J/K.mole)}]-[2mole\times (292.53J/K.mole)]](https://tex.z-dn.net/?f=%5CDelta%20S%5Eo%3D%5B1mole%5Ctimes%20%28245.463J%2FK.mole%29%2B3mole%5Ctimes%20%28202.78J%2FK.mole%29%7D%5D-%5B2mole%5Ctimes%20%28292.53J%2FK.mole%29%5D)
Now we have to calculate the entropy change of reaction for 1.62 moles of reacts at standard condition.
From the reaction we conclude that,
As, 2 moles of has entropy change = 268.74 J/K
So, 1.62 moles of has entropy change = 
Therefore, the entropy change of reaction for 1.62 moles of reacts at standard condition is 217.68 J/K
if I'm not mistaking it would be the second option
Answer:
The mechanical energy produced on burning fossil fuels is transformed into chemical energy stored in carbon dioxide.
Explanation:
When fossil fuels are burnt, mechanical energy is produced. Remember that according to the first law of thermodynamics, energy is neither created nor destroyed but can be transformed from one form to another. Hence the mechanical energy produced when fossil fuels are burnt for industrial use, heating of homes, electricity generation , cooking etc the mechanical energy produced is not 'lost'. It must be transformed in to another form of energy.
In the image the arrow G----> C, shows the mechanical energy produced when fossil fuels are burnt are stored as chemical energy in CO2 bonds. CO2 is found in the atmosphere, hence the arrow point upwards from the source towards the atmosphere (C is the atmospheric reservoir of CO2). The energy is subsequently used by producers to produce chemical energy stored in food.
Molar mass of N = 14 g/molMolar mass of O2 = 32 g/molAdding both masses = 46 g/molActual molar mass/ Empirical molar mass = 138.02 / 46 = 3Now multiplying this co effecient with empirical fomula NO2 = 3(NO2) = N3O6So according to above explanation,D) N3O6, is the correct answer.
