Suppose 310. grams of ethanol (ethyl alcohol) is in an aluminum cup of 90.0 grams. Both of these are at 30.0C. A mass m of ice at – 8.5C is taken from a freezer and added to the alcohol in the cup. The final temperature of all the components is 18.0C. Assuming no heat was lost from the system, calculate the mass m of the ice added.

Respuesta :

Answer:

Explanation:

Given

mass of ethanol [tex]m_e=310\ gm[/tex]

mass of aluminium cup [tex]m_{al}=90\ gm[/tex]

both are at an initial temperature of [tex]T_i=30^{\circ}C[/tex]

specific heat of ethanol [tex]c_e=2.46\ J/g-K[/tex]

specific heat of aluminium [tex]c_{al}=0.9\ J/g-K[/tex]

specific heat of ice [tex]c_i=2.108\ J/g-K[/tex]

specific heat of water [tex]c_w=4.184\ J/g-K[/tex]

Latent heat of fusion [tex]L=334\ J/gm[/tex]

suppose m is the mass of ice added

Heat loss by Al cup and ethanol after [tex]18^{\circ}C[/tex] is reached

[tex]Q_1=(310\times 2.46+90\times 0.9)\cdot (30-18)[/tex]

Heat gained by ice such that ice is melted and reached a temperature of [tex]18^{\circ}C[/tex]

[tex]Q_2=m\times 2.108\times (8.5)+m\times 334[/tex]

Comparing 1 and 2 we get

[tex]m=23.65\ gm[/tex]

Thus 23.65 gm of ice is added