Answer:
Thats a weird question. But I think it changed over time because dresses are really suitable for bike riding. The hem might get caught on the wheel etc. Which is probably why they started wearing trousers and that eventually became a trend.
Thats just a theory though. Not sure of what exactly happened
A case study
I did that already
Answer:
- 484 KJ/mol
Explanation:
The reaction equation is;
CH4(g) + F2 (g) ------> CH3F(g) + HF(g)
The enthalpy of the reaction can be calculated from bond energies using the formula;
ΔHreaction = Bond energy of reactants - bond energy of products
or
ΔHreaction = Bonds broken - bonds formed
[4(413) + 1(155) - 3(413) + 1(485) + 1(567)]
[(1652 + 155) - (1239 + 485 + 567)]
[1807 - 2291]
= - 484 KJ/mol
