Question

How many kilojoules of hear are required to melt a 10.9 gram Popsicle at 0 degrees Celsius & 101.3 kPa? Assume the Popsicle has the same molar mass and heat capacity of water

I know the answer is 334 KJ but I don't know how to get it.

Answer 1

You must supply 3.64 kJ of heat.

Explanation:

The formula for the heat `q` required to melt a substance is

`color(blue)(bar(ul(|color(white)(a/a)q = mΔ_text(fus)Hcolor(white)(a/a)|)))" "`

where

`"mcolor(white)(mm) =` the mass of the substance

`Δ_text(fus)H =` its enthalpy of fusion

In this problem,

`m color(white)(mm)= "10.9 g"`

`Δ_text(fus)H = "333.55 J·g"^"-1"`

`q = 10.9 color(red)(cancel(color(black)("g"))) × "333.55 J·"color(red)(cancel(color(black)("g"^"-1")))= "3640 J = 3.64 kJ"`