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PLEASE HELP MEEE

this is due like in 10 min

how do you explain that 1 OF2 + H2o --> 1 O2 + 2 HF demonstrates that mass is conserved in a chemical l reaction

User Sandos
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1 Answer

3 votes

Answer:

In order to find the two statements, we must first define what the enthalpy of formation and the enthalpy of reaction mean.

Enthalpy of formation:

The change in enthalpy when one mole of substance is formed from its constituent elemetns at standard state.

Enthalpy of reaction:

The change in enthalpy when a reaction occurs and the reactants and products are in their standard states.

Now, we check the statements. The true ones are:

The Hrxn for C(s) + O₂(g) → CO₂(g) is the same as Hf for CO₂

This is true because the formation of carbon dioxide requires carbon and oxygen in their standard states.

The Hf for Br₂(l) is 0 kJ/mol by definition.

Because the bromine is present in its standard state, the enthalpy of formation is 0.

The Hrxn for the reaction 1.5H₂(g) + 0.5N₂(g) → NH₃(g) is the same as the Hf for NH₃(g)

The reactants and products are present in their standard state, and the reaction is the same as the one occurring during the formation of ammonia.

User Brianbruff
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