How Does Adding an Aluminum Rod Affect Water Temperature and Steam Production?

[cogs24]

hi guys

200g copper calorimeter, 200g of water, both intially at 30 degrees. Aluminium rod added to the system, with mass of 250g, final temp is 100 degrees. 10g of water is converted to steam.

first its asking to calulate how much energy is reuiqred to vaporize those 10g to steam

then it asks the find the initial temp of the rod
For this i had:

(0.2 x 387 x 70) + (0.2 x 4186 x 70) = 0.25 x 900 x (T initial - 100)

i tried getting the initial temperature, but it didnt come out, i think i have to include the 10g vaporization of water?

Also, an electric heater has a radiant output of 500W at 150 degrees, so what's the radiant output at 200 degrees?

 

[mfb]

i think i have to include the 10g vaporization of water?

Sure, that is energy from the aluminium rod that was used to evaporate the water. The copper absorbed heat to warm up, the water absorbed heat to warm up to 100 degrees, and then additionally 10 gram absorbed energy to convert to steam. Sum the three and you get the energy the aluminium rod lost.