## Pizza Rolls 3E

$\Delta U=q+w$

Savannah Mance 4G
Posts: 107
Joined: Fri Aug 30, 2019 12:17 am

### Pizza Rolls 3E

Can someone explain why it is false that removing heat from the system is exothermic and the temperature will decrease?

Rachel Yu 1G
Posts: 113
Joined: Fri Aug 09, 2019 12:15 am

### Re: Pizza Rolls 3E

This is false because in phase changes heat can be removed but the temperature will not change. If you look at a heating curve, you'll see that temperature stays constant during a phase change despite the change in heat. i.e. When ice is in the process of melting into water (phase change), heat can be added or removed but the temperature will still remain at 0 degrees Celcius.

Posts: 52
Joined: Thu Jul 11, 2019 12:16 am

### Re: Pizza Rolls 3E

The first part of the statement, that removing heat from a system will be exothermic is true because heat is leaving the system. However as said before phase changes play a role in not changing temperature because heat can be added to go from one phase to the next but not change the temperature in any way.

ThomasNguyen_Dis1H
Posts: 102
Joined: Fri Aug 30, 2019 12:17 am

### Re: Pizza Rolls 3E

If you look at the heating curve, we see that at phase changes the curve is a straight line. At these sections we see that as heat is being added on the x-axis, the temperature of y axis remains the same.

CynthiaLy4F
Posts: 103
Joined: Sat Jul 20, 2019 12:16 am

### Re: Pizza Rolls 3E

This is false because during phase changes, the removal of heat does not necessarily cause temperature to decrease. This can be seen by the plateaus on heating curves.