Phase change

[Riya Sood 4G]

is the delta H positive or negative when ice turns to liquid?

[Suraj Doshi 2G]

This phase change causes the change in enthalpy to be positive (delta H is positive).

[MinuChoi]

Enthalpy will be positive because the molecules must absorb energy to loosen forces on each other and assume more free form.

[Dina Marchenko 2J]

A positive delta H means energy is put in (endothermic) which is what is necessary to break the bonds that holds a solid together into a liquid. That's why change in enthalpy is positive.

[faithkim1L]

Delta H should be positive.

[John Liang 2I]

Because the phase change requires energy, there is a + delta H value. Hope this helps

[KHowe_1D]

Delta H would be positive because the molecules are absorbing energy to "loosen" the bonds.

[Callum Guo 1H]

Positive because you add energy

[Naneeta Desar 1K]

Delta H is positive since melting is breaking bonds and energy is required in order to do so.

[Celine 1F]

In this case, delta H is positive

[Abigail_Hagen2G]

It would be positive, because it requires energy to cause the phase change.

[Isabella Dal Porto 1H]

Breaking the bonds that are holding the solid together requires energy. Thus, delta H is positive since the reaction is endothermic (needs energy/energy absorbed).

[KSong_1J]

Delta H is positive because energy must be used to break the bonds to turn ice into a liquid

[Anish Natarajan 4G]

You're going from a state of lower energy to a state of higher energy when you go from a solid to a liquid (or a liquid to a gas) so the change in enthalpy should be positive

[gconcha]

Because heat (energy) needs to be added to the ice in order to make it undergo a phase change into liquid form, is positive

[Anushka Chauhan2B]

It should be positive

[205389184]

Delta H would be positive when ice turns to liquid

[Nare Nazaryan 1F]

Delta H is positive when ice turns to liquid (applying heat to change from solid to liquid).

[smurphy1D]

Delta H is positive because heat is being added in order to melt the ice

[Madelyn Romberg 1H]

Delta H is positive as the system absorbs energy in order to go to a liquid phase AND the energy remains there to keep it in a liquid phase.

[Megan Kirschner]

A positive delta H means energy is put in, which makes it endothermic, which is what is necessary to break the bonds that holds a solid together into a liquid. That's why the change in enthalpy is positive!