Question

Which of the following element has non-zero enthalpy?
A. Na(s)
C. Hg)
D. Cl2(g)
B. Br2(g)

Answer 1

Answer:

Cl2

Explanation:

I don't know the specific reason behind this.

Answer 2

Among the following, the element that has non-zero enthalpy is $\[B{r_2}(g)\]$.

Explanation:

• The enthalpy of elements in their elemental or natural state is always zero.
• Sodium exists as elemental Na in the solid state. Therefore, its enthalpy is zero.
• Hydrogen exists as a gas in its elemental state. Therefore, it has a zero enthalpy.
• Chlorine also exists as a gas in its elemental state. Thus, it also has a zero enthalpy.
• Bromine exists as a liquid at room temperature. To change it into a gas, some amount of energy must be supplied to it. Therefore, bromine in its gaseous state does not have a zero enthalpy.