Sapling Homework #10

[jordanginyard_]

How do we solve enthalpy? What is the equation to use, is it the q= MC (temp final minus initial temperature) equation ?

[Jagveer 1I]

For this question they want us to find the final temperature, so we will need to use the equation that you described to find it. We need to first calculate the moles of ice and then multiply that by the delta H fus of water and this calculation gives us the heat required to melt the ice, so the enthalpy of fusion of water. The way that you would set up your equation would: enthalpy of fusion of water, which is the value that was just calculated+(mass of ice*specific heat capacity of water*(tfinal-tinitial))=mass of water*specific heat capacity of water*(tfinal-tinitial). Hope this helps.

[Andre Fabian 1F]

Hey!

For this problem you'd use the following equation:
mc(deltaT) + deltaHfus(m) = mc(deltaT)

heat required to change the temperature of the ice + the heat required to melt the ice = heat released from cooling water


Hope this helps!

[alette1a]

The enthalpy that we are calculating for is the heat required to melt the ice; deltaHfusion.
To calculate this, multiply the mass given of ice x the molar mass of ice (H2O) x the given deltaHnaught, using dimensional analysis. The answer should be in J.
To use this calculated enthalpy in the equation:
enthalpy to melt ice + qice = -qwater
which is the same as
enthalpy to melt ice + mCdeltaT(for ice) = -mCdeltaT(for water)

[Ranen_Chang_2G]

The equation would be deltaH fus*mol of water + mC(Tfinal - Tinitial of ice) = -mC(Tfinal-Tinitial of water).

Note that the side with water is negative because it is decreasing in temperature.

Find your mol of water given the grams of ice to multiply with deltaH fusion of ice.

Then just solve for Tfinal.

[Juliana Rosales 1H]

I understand where you're coming from! I had so much trouble trying to find an equation that worked to figure out the answer.

[Ranen_Chang_2G]

Because you would need to account for the heat in the fusion of water (no increase/decrease in temperature), your equation should be . Then plug everything in.