Answer:
B, D
Explanation:
The strategy here is to realize that the ice will be taken from -6.5 ºC to OºC where it will melt.
Lets call q₁ the heat required to bring the ice to 0ºc, q₂ the heat required to bring the phase change from solid to liquid.
q₁ is calculated from the expression
q₁ = s x m x ΔT where m is the mass, s the specific heat of ice ( 2.09 J/gºC ) and ΔT the change in temperature.
q₂ the fusion enthalpy change is calculated from the expression:
q₂ = C x ΔT
where C is the specific heat for the phase change , in this case named AH given in kJ/mol.
We are given all the data needed to calculate q₁, q₂ and qtotal ( q₁ + q₂ )
q₁ = 25.0 g x ( 2.09 J/gºC) x ( 0 - ( -6.5 ºC ) )
q₁ = 339.6 J = 0.339 kJ
q₂ = (25 g/ 18 g/mol) x 6.02 kJ/mol = 1.39 x 6.02 kJ = 8.36 kJ
qtotal = 0.339 kJ + 8.36 kJ = 8.70 kJ
with these calculations, we can now proceed to answer the question:
(a) False AH is theheat capacity for the melting.
(b) True as we determined above
(c) False we only have one phase change, from solid (ice) to liquid
(d) True as calculated above
(e) False as determined in our calculations
