Question

If a person has a dangerously high fever, submerging her in ice water is a bad idea, but an ice pack can help to quickly bring her body temperature down.

How many grams of ice at 0 degrees C will be melted in bringing down a 62kg patient's fever from 40 degrees C to 39 degrees C?

Answer 1

Answer:

775 grams of ice

Explanation:

Heat loss by patient = heat gained by ice

Heat loss by patient = mass×specific heat capacity×(initial temperature - final temperature) = 62×4200×(40-39) = 260,400J

Heat gained by ice = mass × specific latent heat of fusion of ice = m×336000 = 336000m J

336000m = 260,400

m = 260400/336000 = 0.775kg = 0.775×1000 grams = 775 grams of ice

Answer 2

"640 g" of ice at 0°C will be melted.

Given:

• Mass, m = 62 kg

We know,

• Specific heat of human body = 3470 J/kg.C
• Specific heat of ice = 2108 J/kg.C
• Ice's heat of fusion, $L_f$ = 334000 J/kg

As we know,

→ $Heat \ gain \ by \ ice = Heat \ loss \ by \ patient$

or,

→ $mC \Delta t+m L_f = mC \Delta t$

By taking common,

→ $m(C \Delta t+ L_f) = m C \Delta t$

By substituting the values, we get

→ $m(2108\times 1+334000)= 62\times 3470\times 1$

                                  $m = 0.640 \ kg$

or,

                                  $m = 640 \ g$

Thus the above approach is correct.

Learn more about specific heat here:

https://brainly.com/question/14827896