A chemist mixes 100ml of H2O at 30 degrees Celsius and 56.0g of CaOin a calorimeter.

The following reaction occurs"
CaO(s) +H2O(l)--->Ca(OH)2(s) ΔH= -16.0 kcal/mol

The heat capacity Ca(OH)2(s) is 19.2 cal/mol*degreeCelsius and the heat of vaporization of water is 540 cal/g. How much liquid water and how much steam would result?

I would do this.

56 g CaO is 1 mole; it will produce 1 mole Ca(OH)2 in the reaction.
The reaction will evolve 16,000 calories for the 1 mole CaO used.
How much will the water use in moving from 30 C to 100 C?
q = mass H2O x specific heat H2O x (Tfinal-Tinitial) = 100 x 1 x (100-30) = ??approximately 7000 cal.
How much will the Ca(OH)2 absorb?
That will be 1 mole x 19.2 cal/mol x (100-30) = ?? approximately 1400 cal.

Total heat absorbed about 7000+1400 = about 8400 cal. How much heat is left over? 16,000-8400 = about 7600 cal. Where will it go? To vaporize the water to steam. How much will be vaporized.
7600 = mass water vaporized x 540 cal/g and solve for mass water vaporized = about 13 g; therefore, about 13 grams will be steam and 100-13 = ?? will be liquid water at 100 C.

To determine the amount of liquid water and steam that would result, we need to calculate the heat exchanged in the reaction and use it to determine the final phase of water.

First, let's calculate the heat exchanged in the reaction using the given enthalpy change (ΔH) and the amount of CaO used.

The given enthalpy change is -16.0 kcal/mol. Since we know that 56.0g of CaO is used, we need to convert this mass into moles by dividing by its molar mass (56.0 g/mol).

Molar mass of CaO = 40.08 g/mol (Ca) + 16.00 g/mol (O) = 56.08 g/mol

Number of moles of CaO = 56.0 g / 56.08 g/mol = 1.0 mol

Now we can calculate the heat exchanged:
Heat exchanged = ΔH × number of moles of CaO
Heat exchanged = -16.0 kcal/mol × 1.0 mol = -16.0 kcal

Next, let's determine the change in temperature of the water.

The specific heat capacity of Ca(OH)2(s) is given as 19.2 cal/mol*degreeCelsius.

The change in temperature (∆T) can be calculated using the equation:
∆T = Heat exchanged / (Heat capacity × number of moles of Ca(OH)2)

Number of moles of Ca(OH)2 = number of moles of CaO used (according to the balanced equation)

∆T = -16.0 kcal / (19.2 cal/mol*degreeCelsius × 1.0 mol)

Now we can calculate the change in temperature (∆T). Once we have ∆T, we can determine if the water will remain in the liquid phase or transition to steam.

∆T = -16.0 kcal / (19.2 cal/mol*Celsius) ≈ -833.33 degreeCelsius

Since the calculated change in temperature is negative, it means that the water will remain in the liquid phase.

Therefore, all 100 ml (100 g) of water will not evaporate.