How many types of formulas are there in Calc? Explain any two.
Answers
Answer:
3 formulae is your answer
Explanation:
Answer:
The ΔH for the reaction is - 100 KJ/mol
Explanation:
We are given with following reaction,
\sf H_{2}\;+\; Br_{2}\longrightarrow 2\;HBr \; \; \; \;\;\Delta H=\;?H2+Br2⟶2HBrΔH=?
The hypothetical bond energy is also given, which is
1. Bond energy of H-H is 300 KJ/mol
2. Bond energy of Br-Br is 100 KJ/mol &
3. Bond energy of H-Br is 250 KJ/mol
From the formula we know that,
ΔH = ∑ bond energy (reactants) - ∑ bond energy (Products)
Substituting,
⇒ ΔH = [(H-H) + (Br-Br)] - [2 × (H-Br)]
⇒ ΔH = [300 + 100] - [2 × 250]
⇒ ΔH = 400 - 500
⇒ ΔH = - 100
⇒ ΔH = -100 KJ/mol
∴ The ΔH for the reaction is - 100 KJ/mol.
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Note:-
1) 2 is multiplied to the bond energy of products because 2 is the stochiometric coefficient of HBr.
2) Negative sign of enthalpy of fusion indicate that it is an exothermic reaction.