Nitrogen gas consists of a diatomic nitrogen atom. So, the correct answer is B.
Ice is a mixture and it can be a compound at the same time. A mixture is when you have to substance's put together fro example you can mix salt and sugar together. But a compound is when two different elements or molecules are combined. Ice cream is a mixture or cream and sugar mainly.
Answer:
-125 kJ
Explanation:
You calculate the energy required to break all the bonds in the reactants. Then you subtract the energy to break all the bonds in the products.
H₂C=CH₂ + H₂ ⟶ H₃C-CH₃
Bonds: 4C-H + 1C=C 1H-H 6C-H + 1C-C
D/kJ·mol⁻¹: 413 612 436 413 347
The formula relating ΔHrxn and bond dissociation energies (D) is
ΔHrxn = Σ(Dreactants) – Σ(Dproducts)
(Note: This is an exception to the rule. All other thermochemical reactions are “products – reactants”. With bond energies, it’s “reactants – products”. The reason comes from the way we define bond energies.)
<em>For the reactant</em>s:
Σ(Dreactants) = 4 × 413 + 1 × 612 + 1 × 436 = 2700 kJ
<em>For the products:</em>
Σ(Dproducts) = 6 × 413 + 1 × 347 = 2825 kJ
<em>For the system</em>
:
ΔHrxn = 2700 - 2825 = -125 kJ
B. The area of the island is your answer :)
Answer:
ΔH°rxn = -47 kJ
Explanation:
Using Hess´s law for the reaction:
3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g) ,
the ΔH°rxn will be given by the expression:
ΔH°rxn kJ = 2ΔHºf(Fe3O4) + ΔHºf(CO2) - ( 3ΔHºf(Fe2O3) + ΔHºf(CO) )
= 2(-1118) + (-394) - ( 3( -824 ) + ( -111 ) )
= - 47 kJ
