Question

Energy, Hept, and Work 621 > Review Constants Periodic Table Energy cannot be created nor destroyed, but it can be transferred between a reaction and its surroundings. The change in energy AE is positive if the reaction absorbs energy, and it is negative the reaction release energy. You may also see this expressed in Dorms of change in internal energy. AU. For the purposes of this question, AU and we gua. One way a reaction can transfer energy to or from the surroundings is by releasing or absorbing hat. A reaction con also transfer energy in the form of work, through a change in volume. The total change in energy is the sum of the heat and Amole of X reacts a constant pressure of atm via the reactio X() + 4Y()-22/6). AN--75.0 kJ Before the reaction, the volume of the gaseous mixture was 5.00 L. After the reaction, the volume was 2.00 L. Calculate the value of the total energy change Aines Express your answer with the appropriate units. View Available Hints) AE9+ At constant pressure, = AH and w -PAV and so AE - AH-PAV AE. 61. 9 K Submit Previous X Incorrect; Try Again; 4 attempts remaining

Answer 1

Step(1) Given condition, at constant pressure

(∆H°)_p = q = -75.0kJ

Step (2) calculation for work done in the reaction.

w = -P∆V = -P(V₂-V_{​​​​1})

Given Value

P = 43.0atm

V_{​​​​​​2} = final volume = 2.0L

V_{​​​​​​1} = initial volume = 5.0L

So,

w = -(43.0atm)(2.0L - 5.0L)

w = -43.0atm(3.0L)

w = 129.0atm-L

(note :- 1atm -L = 101.325J)

so,

w = (129.0×101.325J)

w = 13070.925J

(because 1000j = 1kJ)

w = 13.07kJ

Step (3) Calculation for change in international energy.

∆E = q +w

∆E = -75.0kJ + 13.07kJ

∆E = -61.9KJ

( ∆E = negative value)