A system delivers 225 j of heat to the surroundings while delivering 645 j if work calculate the change in the internal Chang

Chemistry

2 answers:

Charra [1.4K]4 years ago

3 0

Heat given out to the surroundings by the system = 225 J

Work done by the system on the surroundings = 645 J

According to the energy conservation, the energy can neither be created nor it can be destroyed, it can transform from one form to another. Hence, the energy which is lost to the surrounding as a work done and heat came from the internal energy of the system.

Hence, the change in the internal energy = - 225 - 645 = - 870 Joules

Negative sign means that the internal energy of the system is decreased by 870 Joules

Ipatiy [6.2K]4 years ago

3 0

The change in the internal energy:<u>-870 J</u>

<h3>Further explanation </h3>

The laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created

The equation is:

$\rm \Delta U=Q+W$

Energy owned by the system is expressed as internal energy (U)

This internal energy can change if it absorbs heat Q (U> 0), or releases heat (U <0). Or the internal energy can change if the system does work or accepts work (W)

The sign rules for heat and work are set as follows:

• The system receives heat, Q +

• The system releases heat, Q -

• The system does work, W -

• the system accepts work, W +

Heat can be calculated using the formula:

Q = mc∆T

A 225 Delivers System J Of Heat To The Surroundings While Delivering 645 J Of Work, then

Q release heat = -225 J

The system does work, W = -645 J

the change in the internal energy, ∆E, of the system

∆E / ∆U = Q + W