For the reaction H2 + I2 ⇋ 2HI, ΔH and ΔU are related as

40 views

closed
For the reaction H2 + I2 ⇋ 2HI, ΔH and ΔU are related as
1. ΔH > ΔU
2. ΔH < ΔU
3. ΔH = ΔU
4. Can't say

by (30.0k points)
selected

Correct Answer - Option 3 : ΔH = ΔU

The correct answer is ΔH = ΔU.

As we know,

ΔH = ΔU + Δng​RT

Here,

H2​(g) + I2(g) ⟶ 2HI(g)

Δng = 0 [ Δn= no of gaseous product - no of gaseous reactant] which is 2 - (1 + 1) = 0

so, ΔH =ΔU

• Isolated System – An isolated system cannot exchange both energy and mass with its surroundings.
• The universe is considered an isolated system.
• Closed System – Across the boundary of the closed system, the transfer of energy takes place but the transfer of mass doesn’t take place.
• Refrigerator, compression of gas in the piston-cylinder assembly are examples of closed systems.
• Open System – In an open system, the mass and energy both may be transferred between the system and surroundings.
• A steam turbine is an example of an open system.
• There are four types of thermodynamic process that have their unique properties, and they are:
• Adiabatic Process – A process where no heat transfer into or out of the system occurs.
• Isochoric Process – A process where no change in volume occurs and the system does no work.
• Isobaric Process – A process in which no change in pressure occurs.
• Isothermal Process – A process in which no change in temperature occurs.