J.R. S. answered 11/15/23
Ph.D. University Professor with 10+ years Tutoring Experience
2 C6H6 + 15 O2 ==> 12 CO2 + 6 H2O + 6542 kJ (exothermic)
calculate heat generated from 8.600 g of C6H6:
molar mass C6H6 = 78.11 g
8.600 g x 1 mol / 78.11 g = 0.1101 mols x 6542 kJ / 2 mols = 360.1 kJ of heat
Next, we use this amount of heat to find the final temperature of the water, as follows:
q = mC∆T
q = heat = 360.1 kJ = 360100 J
m = mass of water = 5691 g
C = specific heat of water = 4.184 J/gº
∆T = change in temperature of the water = ?
Solving for ∆T, we have...
∆T = q / (m)(C) = 360100 J / (5691 g)(4.184 J/gº)
∆T = 15.1º
Final temperature of the water = 21º + 15.1º = 36º (2 sig.figs.