# Heathcapacity problem help (1 Viewer)

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#### Izekid

Here's my problem

A box with the heathcapacity 80J/K contains 0,2kg water. The box and the water has together the temperatur 18*C. We put 0,050kg ice with the temperature -15*C in the box of water. Investigate if all ice melts. Don't take with heath from the surrondings.

Well for this problem I though like this

0,2Kg Water * 4,19(water's heath capacity) = 0,838 + 80J/K =0,8380008

Then I took the Ice capacity = 0,050kg * 4,19 = 0,2095

0,8380008-0,2095 =0,62858

Then lets do it to Kelvin 273+18=291K
273-15=258K

0,62858 * -33 K = -20,7314

But that doesn't say me nothing if the Ice has melted?

How do I know that?

#### Doc Al

Mentor
Think this way: How much energy is required to melt the ice? You must first raise the temperature from -15 to 0, then melt it.

Now ask: Does the box + water have enough energy to melt that ice? How much energy will the box + water release if it cooled from 18 degrees to 0?

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