Achieve Weeks #3-4 #10

[Jamie Lin 1K]

"An ice cube with a mass of 50.8 g at 0.0 ºC is added to a glass containing 425 g of water at 45.0ºC . Determine the final temperature of the system at equilibrium. The specific heat capacity of water, Cs , is 4.184 J/g ºC , and the standard enthalpy of fusion, ΔH∘fus , of water is 6.01×103 J/mol . Assume that no energy is transferred to or from the surroundings."

Why is the same specific heat capacity used for water also used for ice? I thought the specific heat capacity for ice would be 2 J/gºC.

[Xuan Lai 1H]

The reason we use the specific heat of water is because you will account for the phase change using the standard enthalpy of fusion. To do this, you will convert the grams of ice to mols and multiply by the enthalpy of fusion. When you set up the equation to solve for the final temperature, you will add this heat to it. Hope that helps!

[Cory Poon 3G]

We don't use the specific heat of ice because we need to account for the enthalpy of fusion. When we calculate this, we have to find out the enthalpy of the ice turning into water immediately because it starts melting immediately.