a student observed the shape of the moon once every 7 days during the month of June. which of the following sets of drawings sho
ws how the moons shape could have changed during the month of June?
1 answer:
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The enthalpy change : -196.2 kJ/mol
<h3>Further explanation </h3>The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)
The value of ° H ° can be calculated from the change in enthalpy of standard formation:
∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)
Reaction
2 H₂O₂(l)-→ 2 H₂O(l) + O₂(g)
∆H ° rxn = 2. ∆Hf ° H₂O - 2. ∆Hf °H₂O₂
Answer:
T₂ = 43.46 °C
Explanation:
Given that:
The heat of the formation of carbon dioxide = - 393.5 kJ/mol (Negative sign suggests heat loss)
It means that energy released when 1 mole of carbon undergoes combustion = 393.5 kJ = 393500 J
Heat gain by water = Heat lost by the reaction
Thus,
For water:
Mass of water = 5100 g
Specific heat of water = 4.18 J/g°C
T₁ = 25 °C
T₂ = ?
Q = 393500 J
So,
T₂ = 43.46 °C