In: Chemistry
in an experiment, 15.0 g of ice at -30 celsius is converted into steam with a temperature of 115 celsius. How much energy is required for this process? DHvap= 2260 J/g; DHfus= 334 J/g; cs(ice)= 2.06 J/(g celsius; cs(water)= 4.18 J/(g celsius; cs(steam)= 1.99 J/(g celsius))
ice converted to 00C water q1 = mcT
= 15*2.06*(0-(-30)
= 15*2.06*30 = 927J
heat of fustion of ice q2 = m*H fus
= 15*334 = 5010J
water converted to vapor q3 = mcT
= 15*4.18*(100-0) = 6270J
water vapor converted to 1150C q4 = mcT
= 15*1.99*(115-100)
= 447.75J
heat of vaporisation q5 = m*Hvap
= 15*2260 = 33900J
The total energy q = q1+ q2+q3+q4+q5
= 927+5010+6270+447.75+ 33900 = 46554.75J