The amount of joules of heat that are lost when 150.0 g of steam are cooled from 124 °c to 86 °c is = -11343 joules
calculation
heat(Q) = mass(m) x specific heat capacity(C) x change in temperature (ΔT)
where,
Q=? joules
M=150.0 g
C for steam = 1.99 j/g/°c
ΔT= 86°c-124°c = -38°c
Q is therefore = 150.0 g x 1.99 j/g/°c x -38°c =-11343 joules
