A mole of X reacts at a constant pressure of 43.0 atm via the reaction

X (g) + 4Y (g) →2Z (g), ΔH∘=-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, ΔE, in kilojoules.

Question

Robert Peck

Chemistry

8 August, 09:20

A mole of X reacts at a constant pressure of 43.0 atm via the reaction

X (g) + 4Y (g) →2Z (g), ΔH∘=-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, ΔE, in kilojoules.

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Answers (1)

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Deangelo Rivera · Answer 1

Sobaric transition, first law: H=ΔU+w

for a gas expansion: w = Pext ∗ΔV

to convert to joules, you need the gas constants.

R = 0.08206 L atm/mol*K, R=8.314 J/mol*K

w = Pext ∗ΔV∗ 8.314 J/mol∗K/0.08206 L atm/mol∗K

ΔU=ΔH-[ Pext ∗ΔV∗ 8.314 J/mol∗K/0.08206 L atm/mol∗K ]

ΔU=-75000 J-[ (43.0atm) ∗ (2-5) L∗ 8.314 J/0.08206 L atm ]

Then you need to convert to kJ by the way U=E, internal energy.

A mole of X reacts at a constant pressure of 43.0 atm via the reactionX (g) + 4Y (g) →2Z (g), ΔH∘=-75.0 kJBefore 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, ΔE, in kilojoules.

A mole of X reacts at a constant pressure of 43.0 atm via the reaction

X (g) + 4Y (g) →2Z (g), ΔH∘=-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, ΔE, in kilojoules.