Is this exothermic or endothermic? EXPLAIN
C2H2+H2-----> C2H4
Is this exothermic or endothermic? EXPLAIN
C2H2+2H2---->C2H6
Is this exothermic or endothermic? EXPLAIN
C2H4+ H2 ----> C2H6
dHrxn = (n*dHproducts) - (n*dHreactants)
Then check the sign. If dHrxn is - the reaction is exothermic; if dHrxn is positive the reaction is endothermic.
exo
To determine if a reaction is exothermic or endothermic, we need to consider the overall energy change of the reaction.
For the reaction C2H2 + H2 → C2H4:
This reaction involves the formation of C2H4 from C2H2 and H2. In this case, there is a breaking of the triple bond in C2H2 and the formation of a double bond in C2H4.
The breaking of a bond requires energy input, while the formation of a bond releases energy. In this reaction, the formation of the double bond in C2H4 releases more energy than the energy required to break the triple bond in C2H2 and the formation of the single bond in H2. Therefore, this reaction is exothermic, meaning it releases heat and the energy change is negative ΔH.
For the reaction C2H2 + 2H2 → C2H6:
This reaction involves the formation of C2H6 from C2H2 and 2H2. Here, there is a breaking of the triple bond in C2H2 and the formation of a single bond in C2H6.
Similar to the previous reaction, the breaking of a bond requires energy input, while the formation of a bond releases energy. In this reaction, the formation of the single bond in C2H6 releases more energy than the energy required to break the triple bond in C2H2 and form the two single bonds in H2. Therefore, this reaction is also exothermic, meaning it releases heat and the energy change is negative ΔH.
For the reaction C2H4 + H2 → C2H6:
This reaction involves the addition of H2 to C2H4 to form C2H6. Here, a double bond is being converted to a single bond.
The conversion of a double bond to a single bond usually involves energy release. In this case, the formation of the single bond in C2H6 releases energy. Therefore, this reaction is also exothermic, meaning it releases heat and the energy change is negative ΔH.
To determine whether a reaction is exothermic or endothermic, you need to analyze the change in enthalpy (∆H) of the reaction. Enthalpy refers to the heat energy exchanged during a chemical reaction.
In general, if the ∆H value is negative, the reaction is exothermic, meaning it releases heat to the surroundings. Conversely, if the ∆H value is positive, the reaction is endothermic, which means it absorbs heat from the surroundings.
Now, let's apply this concept to the given reactions:
1. C2H2 + H2 → C2H4:
To determine if this reaction is exothermic or endothermic, you would need to refer to experimental data or enthalpy changes provided in a reference table. Without concrete data, we cannot definitively state whether it is exothermic or endothermic. You would need to consult enthalpy values or conduct experiments to determine the sign of ∆H for this reaction.
2. C2H2 + 2H2 → C2H6:
Similarly, without specific enthalpy information, we cannot determine if this reaction is exothermic or endothermic. Thermochemical data or laboratory analysis would be necessary to determine the value and sign of ∆H for this reaction.
3. C2H4 + H2 → C2H6:
Again, without access to enthalpy data, we cannot conclude whether this reaction is exothermic or endothermic. Consultation of enthalpy values from reliable sources or performing experimental measurements are required to determine the sign of ∆H for this reaction.
To summarize, without enthalpy data, it is not possible to determine whether a reaction is exothermic or endothermic. It is vital to refer to appropriate thermochemical data or perform experiments to obtain the needed information.