Answer:
a) ΔH°rxn = -9.2kJ/mol
b) ΔH°rxn = -9.2kJ/mol
Explanation:
Using Hess's law, you can find ΔH of a reaction from ΔH of formation of the substances involved in the reaction, thus:
ΔH°rxn = ∑(BE(reactants)) − ∑(BE(products))
Or:
ΔH°rxn = ∑(nΔH°f (products)) − ∑(mΔH°f (reactants))
For the reaction:
H₂(g) + I₂(g) → 2HI(g)
a) Using the first equation:
ΔH°rxn = ΔH (H-H) + ΔH (I-I) - 2ΔHBE (H-I)
ΔH°rxn = 436.4kJ + 151kJ - 2×298.3kJ
<em>ΔH°rxn = -9.2kJ/mol</em>
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b) Using the second equation:
ΔH°rxn = 2Δ°f (HI) − ΔH°f (H₂) - ΔH°f (I₂)
ΔH°rxn = 2×25.9kJ - 0kJ - 61.0kJ
<em>ΔH°rxn = -9.2kJ/mol</em>
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Answer: 7.025959200000001
Explanation:
Granite is stronger, and it doesn't grow mold in the rain. It also looks better than marble and is easier to carve.
See , from the equation we can see that for forming two mole of H2O 2Mole of H2 has to react.
Mass of 2 Mole H2O is 18*2gm or 36gm.
So for forming 36 gm H2O 2×2 I.e. 4 gm H2 has to take part in reaction.
Therefore, to form 1 gm H2O 4÷36 gm of H2 has to take part.
So, for forming 47gm H2O (4÷36)×47 gm H2 has to take part
I.e. 5.22 gm of H2 has to take part
So, ans is 5.22 gm of hydrogen.
Hope it helps!!!
