<u>Answer:</u> The value of
for the reaction is 1051.93 J/K
<u>Explanation:</u>
Entropy change is defined as the difference in entropy of all the product and the reactants each multiplied with their respective number of moles.
The equation used to calculate entropy change is of a reaction is:
![\Delta S^o_{rxn}=\sum [n\times \Delta S^o_{(product)}]-\sum [n\times \Delta S^o_{(reactant)}]](https://tex.z-dn.net/?f=%5CDelta%20S%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20S%5Eo_%7B%28product%29%7D%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20S%5Eo_%7B%28reactant%29%7D%5D)
For the given chemical reaction:

The equation for the entropy change of the above reaction is:
![\Delta S^o_{rxn}=[(2\times \Delta S^o_{(Cr_2O_3(s))})]-[(4\times \Delta S^o_{(Cr(s))})+(3\times \Delta S^o_{(O_2(g))})]](https://tex.z-dn.net/?f=%5CDelta%20S%5Eo_%7Brxn%7D%3D%5B%282%5Ctimes%20%5CDelta%20S%5Eo_%7B%28Cr_2O_3%28s%29%29%7D%29%5D-%5B%284%5Ctimes%20%5CDelta%20S%5Eo_%7B%28Cr%28s%29%29%7D%29%2B%283%5Ctimes%20%5CDelta%20S%5Eo_%7B%28O_2%28g%29%29%7D%29%5D)
We are given:

Putting values in above equation, we get:
![\Delta S^o_{rxn}=[(2\times (881.2))]-[(4\times (23.77))+(3\times (205.13))]\\\\\Delta S^o_{rxn}=1051.93J/K](https://tex.z-dn.net/?f=%5CDelta%20S%5Eo_%7Brxn%7D%3D%5B%282%5Ctimes%20%28881.2%29%29%5D-%5B%284%5Ctimes%20%2823.77%29%29%2B%283%5Ctimes%20%28205.13%29%29%5D%5C%5C%5C%5C%5CDelta%20S%5Eo_%7Brxn%7D%3D1051.93J%2FK)
Hence, the value of
for the reaction is 1051.93 J/K
The nuclear fusion<span> in our </span>sun<span> combines two </span>hydrogen atoms<span> (the smallest and lightest </span>atoms<span>) together to </span>form<span> one </span>helium atom<span> (a slightly larger </span>atom). <span>During the process some of the </span>mass<span> is converted into energy.</span>
You would use the formula:
n =

Where m is the mass, and M is molar mass (the periodic table would be used for this)
In this case, we need to rearrange the formula to find m
m = nM
= 5.40 x 6.941
= 37.5g
Hope this helped! Ask me if there's any part of the working you don't understand :)