Answer:
2Na + Br2 = 2NaBr
Explanation:
In order to balance a chemical equation you make the make sure both sides have the same number of atoms on each side, you do this by multiplying on both sides as if it was a algebraic equation.
Na+ Br2 = NaBr
Na × 2 = Na2
Na × 2 = Na2
Br × 2 = Br2
2Na + Br2 = 2NaBr
Hope this helps.
Answer : The correct option is, (b) +115 J/mol.K
Explanation :
Formula used :

where,
= change in entropy
= change in enthalpy of vaporization = 40.5 kJ/mol
= boiling point temperature = 352 K
Now put all the given values in the above formula, we get:



Therefore, the standard entropy of vaporization of ethanol at its boiling point is +115 J/mol.K
Always use least amount of sig figs possible. So this 9.7 would be (answer): 2 sig figs