J.R. S. answered 01/26/21
Ph.D. University Professor with 10+ years Tutoring Experience
q = mC∆T
q = heat
m = mass
C = specific heat
∆T = change in temp
heat lost by steam must equal heat gained by water (conservation of energy)
heat lost by steam = (0.510 g)(1.89 J/gº)(105.4 - Tf) + (0.510 g)(2260 J/g) = 101.6 - 0.9639Tf
heat gained by water = (4.62 g)(4.184 J/gº)(tf - 14.2) = 19.3Tf - 274.5
101.6 - 0.9639Tf = 19.3Tf - 274.5
20.26Tf = 376.1
Tf = 18.6ºC