Answer:
=C₄H₄O₂
Explanation:
Given the empirical formula of a molecule, the he the quotient of the molecular mas and and the empirical mass=constant.
84.0 g/mol/mass of(C₂H₂O)=constant
=84/(12×2+1×2×16)
=84/42
=2
Therefore, the molecular formula is (C₂H₂O)₂=C₄H₄O₂
Answer : The value of 
for this reaction is 36.18 kJ
Explanation :
First law of thermodynamic : It states that the energy can not be created or destroyed, it can only change or transfer from one state to another state.
As per first law of thermodynamic,
where,
= internal energy of the system
q = heat added or rejected by the system
w = work done
As we are given that:
q = 38.65 kJ
w = -2.47 kJ (system work done on surrounding)
Now put all the given values in the above expression, we get:
Therefore, the value of for this reaction is 36.18 kJ
Umm...Well...
Heisenberg's Uncertainty Principle says that we can never know both the position and rate of change of a particle at any time. We can only know one or the other. This leads to rather silly jokes that deal with uncertainty, probability, and superposition. So, saying that "Heisenberg may have slept here" is essentially saying that it is uncertain if Heisenberg slept there or not, making for a rather silly, but slightly unfunny physics joke.
