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44 votes
How much heat is needed to change 65 g of ice to melt into water at 0ºC ?

User Walk
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2 Answers

29 votes
29 votes

Hey there! I'll try to provide you with my best answer.

Answer: 21710 J

You need to quote the latent heat of fusion of water first which is 3.34 * 10^5 J/kg.

So to do this you can use the formula:

Heat required= Latent heat of fusion * mass (must be in kg)

The question asks for how much heat is needed so we will find heat required. We must also know the latent heat of fusion of the liquid that is to be melt. In this case, it is water so the latent heat of fusion of water is 3.34*10^5 J/kg. And the mass of water is 65 grams. When converted to kg it is 0.065 kg. Now place the values according to the formula.

Heat required= 3.34 * 10^5 * 0.065

= 21710

So, 21710 joules of heat is needed to change 65 grams of ice to melt into water at 0ºC

Note: Both the ice and the water are assumed to be at 0° C of course, if different temperatures are specified you will need the heat capacities of ice, and of liquid water.

Sorry for making it too long. And hope it helped!! ^^

User Flynn
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3.1k points
21 votes
21 votes

Answer:

33.4kJ.

Step-by-step explanation:

Using the equation for a change in temperature and the value for water from Table 1, we find that Q = mLf = (1.0 kg)(334 kJ/kg) = 334 kJ is the energy to melt a kilogram of ice. This is a lot of energy as it represents the same amount of energy needed to raise the temperature of 1 kg of liquid water from 0ºC to 79.8ºC.

User Joko Wandiro
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2.8k points