The melting point is the temperature a substance must reach to go into its liquid phase (or solid) and a boiling point is the temperature a substance must reach to go into its gas phase (or liquid). For example, water must be 0ºC to melt or freeze and 100ºC to boil.
Answer:
177.8kJ/mol
Explanation:
In this reaction, the heat of decomposition is the same as the heat of formation. This is a decomposition reaction.
Given parameters:
ΔHf CaCO₃ = -1206.9kJ/mol
ΔHf CaO = −635.6 kJ/mol
ΔHf CO₂ = −393.5 kJ/mol
The heat of decomposition =
Sum of ΔHf of products - Sum of ΔHf of reactants
The equation of the reaction is shown below:
CaCO₃ → CaO + CO₂
The heat of decomposition = [ -635.6 + (-393.5)] - [−1206.9 ]
= -1029.1 + 1206.9
= 177.8kJ/mol
DiPhosphorus pentoxide or pentaoxide
Particles of gas are more scarcely placed as compared to that of liquid.
the intermolecular forces will be less in gaseous state and hence is less stable
B will make little difference to reaction rate while C and D will reduce the reaction rate. So the answer is A. adding heat energy to the reactants
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