Practice question
Question
How much heat is required to raise 0.4kg of water from 15∘C to 85∘C and then convert 0.25kg to steam at 100∘C in a 0.2kg silver calorimeter initially at 15∘C? (Specific heat of water = 4186J kg−1K−1, silver = 236J kg−1K−1, latent heat of vaporization = 2.256×106J kg−1)
Explanation
Q1 = (0.4×4186+0.2×236)×(85−15) = (1674.4+47.2)×70 = 1721.6×70 = 120512J (to 85°C). Q2 = (0.4×4186+0.2×236)×(100−85) = 1721.6×15 = 25824J (to 100°C). Q3 = 0.25×2.256×106 = 564000J (vaporization). Total: Q = 120512+25824+564000 = 710336J = 710.34kJ.
Discussion
Comments
Please log in to join the discussion.
Login to commentNo comments yet. Be the first to start the discussion.