# How much ice must melt at 0 deg. C to gain 6 g of mass?

• PhyzicsOfHockey
In summary, the conversation discusses finding the amount of ice that must melt at 0 degrees Celsius to gain 6 grams of mass. One person suggests using the equation E=mc^2 and calculating the energy absorbed by the ice, while the other suggests using the specific heat of ice to find the required amount of ice. The conversation also mentions the rules of posting in the homework section on the forum.

## Homework Statement

This is all that is given.

How much ice must melt at 0 deg. C to gain 6 g of mass?

## Homework Equations

I don't know any Relevant equations to this problem.

## The Attempt at a Solution

I have tried leaving mass as a variable and using Latent Heat Energys too. I have no idea what to set equal to what because i don't have equations to work with this problem.

Hmm I think some use of E=mc2 is needed here. If you can find the energy of 6g then assume that is the energy 'absorbed' by a block of ice to turn it to water.

Huh?

Kurdt said:
Hmm I think some use of E=mc2 is needed here. If you can find the energy of 6g then assume that is the energy 'absorbed' by a block of ice to turn it to water.

When the ice melts, energy is absorbed. I get an equiv of 6g = 1.3e14 cal and it takes 79.71 cal/g to melt ice. So it seems to require 1.617e6 metric tons, a cube about 117 m on a side.

rdx said:
When the ice melts, energy is absorbed. I get an equiv of 6g = 1.3e14 cal and it takes 79.71 cal/g to melt ice. So it seems to require 1.617e6 metric tons, a cube about 117 m on a side.

Well that's how I'd do it. If you can see any other intention in the question please feel free to contribute.

I must say if you're going to post in other peoples threads in the homework section. Do not post what could be considered full answers as this is against the rules (even if you have doubts over the method).

Kurdt said:
Well that's how I'd do it. If you can see any other intention in the question please feel free to contribute.

I must say if you're going to post in other peoples threads in the homework section. Do not post what could be considered full answers as this is against the rules (even if you have doubts over the method).

"Against the rules?" How very strange. I seems to assume a monolithic learning style. Where rules?

## 1. How do you calculate the amount of ice that must melt at 0 deg. C to gain 6 g of mass?

To calculate this, we can use the formula Q = m x Lf, where Q is the amount of heat gained, m is the mass of ice, and Lf is the latent heat of fusion for water. Since we know the mass (6 g) and the latent heat of fusion for water (334 J/g), we can solve for the amount of ice that must melt.

## 2. Why does the melting point of ice change when it gains mass at 0 deg. C?

The melting point of ice is the temperature at which it changes from a solid to a liquid. When ice gains mass, it is absorbing energy and increasing in temperature. As a result, the melting point also increases, since it requires more energy to overcome the intermolecular forces holding the molecules together.

## 3. How do you account for any impurities in the ice when calculating the amount that must melt?

Impurities in ice can affect its melting point and the amount that must melt to gain a certain mass. To account for this, we can use a correction factor to adjust the latent heat of fusion for water. This correction factor takes into account the impurities and their effect on the melting point of the ice.

## 4. Is there a difference in the amount of ice that must melt if the initial mass is in the form of crushed ice versus a solid block?

Yes, there is a difference. When the initial mass is in the form of crushed ice, the surface area is increased, allowing for faster heat transfer and a more efficient melting process. This means that a smaller amount of ice will need to melt to gain the same mass compared to a solid block of ice.

## 5. What other factors may affect the amount of ice that must melt at 0 deg. C to gain 6 g of mass?

Other factors that may affect this process include the temperature of the surroundings, the presence of any insulating materials, and the rate of heat transfer. These factors can impact the efficiency of the melting process and ultimately affect the amount of ice that needs to melt to gain the desired mass.