Dmitri Mendeleev, he realized that the physical and chemical properties of elements were related to their atomic mass and arranged them into groups (columns)
Answer:
a) ΔU = 370 KJ
b) Endothermic
Explanation:
a)
The change in energy of the mixture can be given by first law of thermodynamics as:
ΔQ = ΔU + W
ΔU = ΔQ - W
where,
ΔQ = change in heat energy of system
ΔU = Change in internal energy of gases
W = Work done on gases = - 155 KJ
For an isobaric process (i.e constant pressure) we know that:
ΔQ = change in enthalpy = ΔH
ΔQ = 215 KJ
Therefore, using values in the equation, we get:
ΔU = 215 KJ - (-155 KJ)
<u>ΔU = 370 KJ</u>
b)
Since, the enthalpy of products is greater than the reactants. Therefore, this is an <u>endothermic reaction</u>.