Answer:
ΔH = 200 kJ/mol
Explanation:
Step 1: Data given
activation energy (Ea) is: 450 kJ/mol
activation energy (Ea) of the reverse reaction is 250 kJ/mol
Step 2: The balanced equations
C4H10 ---> C2H6 + C2H4 Ea = 450 kJ/mol
C2H6 + C2H4 ---> C4H10 Ea = 250 kJ/mol
Step 3: Calculate ΔH
Since the reverse reaction has a lower activation energy, this means we need less reaction for the reverse reaction to happen. We can say the reaction absorbs energy, so this is the endothermic reaction.
Ea ( of the forward reaction) = ΔH + Ea (of the reverse reaction)
ΔH = Ea ( of the forward reaction) - Ea (of the reverse reaction)
ΔH = 450 kJ/mol - 250 kJ/mol
ΔH = 200 kJ/mol
Since the reactionis endothermi, ΔH is positive
Answer:
The statement d) is true: The entropy of the universe is always increased in a spontaneous process.
Explanation:
a), b), c) and e) are false.
a) When no heat exchange occurs between the system and its surroundings
, this process is called an adiabatic process. Because the system does work on the surroundings, w is a negative quantity and there is a decrease in the system’s internal energy (since it cannot exchange heat, it will have to use its internal energy to do work).
b) Breaking a bond will always require energy, whereas forming a bond releases energy. Therefore, if more bonds are broken than formed, the enthalpy of a reaction will be positive.
c) The second law of thermodynamics states that the entropy of the universe increases in a spon
taneous process and remains unchanged in an equilibrium process. Therefore, the entropy of the universe is not always constant.
d) True.
e) According to the Gibbs equation, if ΔH is negative and ΔS is negative, then ΔG will be negative only when TΔS is smaller in magnitude than ΔH. This condition is met when T is small.
Answer:
You know that nitrogen-14 has 7 protons in the nucleus because it is an isotope of nitrogen, which has an atomic number equal to 7 . Because nitrogen-14 is a neutral atom, the number of protons it has in its nucleus must be equal to the number of electrons that surround its nucleus.
Karst topography can cause drinking water to become more polluted