Answer:
283.725 kJ ⋅ mol − 1
Explanation:
C(s) + 2Br2(g) ⇒ CBr4(g) , Δ H ∘ = 29.4 kJ ⋅ mol − 1
Br2(g) ⇒ Br(g) , Δ H ∘ = 111.9 kJ ⋅ mol − 1
C(s) ⇒ C(g) , Δ H ∘ = 716.7 kJ ⋅ mol − 1
4*eqn(2) + eqn(3) ⇒ 2Br2(g) + C(s) ⇒ 4 Br(g) + C(g) , Δ H ∘ = 1164.3 kJ ⋅ mol − 1
eqn(1) - eqn(4) ⇒ 4 Br(g) + C(g) ⇒ CBr4(g) , Δ H ∘ = -1134.9 kJ ⋅ mol − 1
so,
average bond enthalpy is = 283.725 kJ ⋅ mol − 1
Answer:
To interpret a 13C-NMR spectrum we will use some standards very simple. A 13C-NMR spectrum gives us the following information:
1. Indicates the number of non-equivalent carbons in the molecule.
2. Measuring the chemical shift we can intuit the environment
electronic and determine the next functional groups.
3. In this case we cannot count on integration since the different
carbons have different relaxation times.
The number of peaks in the spectrum indicates the number of types of carbon present in the analyzed substance.
The factors that influence the chemical shift of the signals in the 13C NMR are:
Explanation:
The nuclear magnetic resonance of C13 is complementary to that of H1. This technique is used to determine the magnetic environment of carbon atoms.
