Please show the steps in the path to get to the final asnwer in terms of reactio

ID: 891309 • Letter: P

Question

Please show the steps in the path to get to the final asnwer in terms of reactions

20 grams of steam at 120 °C and 300 g of liquid water at 25 °C are brought together in an insulated flask. The pressure remains at 1 atm throughout.

( Write out the step by step path you use for the calculations)

Given: Cp’ (H2O, 1iq) = 4.184 J/K g, Cp’ (H2O, gas) = 1.86 J/K g, and

H’vaporization = 2257 J/g at 100°C

a)What is the final temperature of the system and which phase or phases are present?

b)Calculate the S for the system, surroundings & universe for this transformation.

heat released by 20 g of steam when it comes to 1000C = mass of steam*Cp*change in temperature = 20*1.86*20 = 744 J

Heat released by steam when it comes to 1000 C water = mass of heat *delta Hvap = 20*2257 = 45150 J

Now, change in temperature of the water at 250C after absorbing (45150+744) J of heat =

total heat absorbed/(mass of water*Cp of H2O(l)) = 36.56 0C

Hence, final temperature of water present initially at 25 0C = 61.56 0C

Now, let the water (formed from steam) present at 100 0C comes to a final temperature of T 0C

and the water present at 61.56 0C comes to T'0C

Thus, heat released by water at 100 0C = heat absorbed by water at 61.56 0C

or, 20*4.184*(100-T) = 300*4.184*(T' - 61.56)

Now, T = T'

Thus, 100 - T = 15(T-61.56)

or, T = 63.96 0C

Hence the final temperature of the system will be 63.96 0C and only liquid phase will be present