Answer:
-753kJ of energy are involved
Explanation:
Based on the reaction:
Fe₂O₃(s) + 2 Al(s) → Al₂O₃(s) + 2 Fe(s) ΔH°rxn = -852 kJ
<em>When 2 moles of Fe are produced, there are released -852kJ.</em>
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98.7g of Fe are:
98.7g Fe × (1mol / 55.845g) = 1.767 moles of Fe
If 2 moles of Fe are producen when -852 kJ of energy are involved, 1.767 moles of Fe envolved:
1.767mol × (-852kJ / 2mol Fe) = <em>-753kJ of energy are involved</em>
Reaction on positive electrode (cathode):
PbSO₄₍s₎ + 2H₂O₍l₎ → 2e⁻ + PbO₂₍s₎ + 4H⁺₍aq₎ + SO₄²⁻₍aq₎.
s - solid.
l - liquid.
aq - dissolve in water.
PbSO4 is converted to Pb at one electrode (anode) and to PbO₂ at the other (cathode). Lead battery can be recharged, during recharging, an external source of energy is used.
Creados entre los 800 y los 1500 o inventos que llevan de creación ese tiempo,puedes ser la pregunta un poco específica?
In chemistry the need for standards when measuring quantities are in place for accurate measurement that is recognized world wide. This way, no matter what language people use, they will always understand there standards.