# Quantity of Heat/Specific Heat Water+Iron

• Kaleb
In summary, 20 degrees C water will lose 1760.04 cal/g of heat while 40 degrees C iron will gain 1004.84 cal/g of heat. In equilibrium, the temperature of both substances will be 28 degrees C.
Kaleb
[SOLVED] Quantity of Heat/Specific Heat Water+Iron

## Homework Statement

Exact Problem:

What will be the final temperature of 100g of 20 degrees C water when 100g of 40 degrees C iron nails are submerged in it. (The specific heat of iron is .12 cal/g C. Here you should equate the heat gained by the water to the heat lost by the nails.)

## Homework Equations

Q = cm(change in)t

Q = quantity of heat

c = specific heat
(water = 4.184J/g or 1 cal/g)
(iron = .502J/g or .12 cal/g)

m = mass
100g + 100g = 200g total substance(water+iron)

t = temperature
(40(final)-20(initial))

## The Attempt at a Solution

I feel I slightly understand what I am supposed to do but the part where it says I need to find the heat lost by iron and the heat gained by water I am totally confused about. Heres my attempt: My assumption is that I need to do two different calculations and difference them out. Also if someone could point me in the right direction to be able to post real equations instead of what I have shown that would be so awesome.

Iron First:
Q = cm(Tf-Ti)

Q = .502J*100g(40-20)

Q = 1004J of Energy Lost

Water Second:

q = 4.184*100g(40-20)

Q = 8368J of Energy Gained

8368J - 1004J = 7364J of Energy or 1760.04cal/g

I have tried numerous ways to find the temperature difference, lost and gained but I am clueless. Also I can't figure out where to transfer back into Celcius. By my calc's it would have gained like 1700 degrees haha. >.> I feel dumb... Anyways TIPS are always appreciated in advance. Constructive critism is appreciated as well, and well anything else that can make me a better poster is welcome too. ^^ thanks!

Your only problem appears to be that you have not read the problem correctly and don't seem to know what is being asked! Your start is correct but why are you using 40 degrees and 20 degrees as "initial" and "final" temperatures for both water and iron?

You also say
8368J - 1004J = 7364J of Energy or 1760.04cal/g "
which you should realize makes no sense. The question was "What will be the final temperature" and that's not even a temperature.

20 degrees is the initial temperature for the water and 40 degrees is the initial temperature for the iron. The final temperature of both will be the same, of course, so just call that "T".

Iron: Energy lost Q = .502J/g*100g(T- 40) and
Water: Energy gained q = 4.184J/g*100g(T-20) and they must be equal. Solve for T.

I see the fault, Thanks a bunch Ivy. You have saved my day and made me feel all the more dumb . That was a joke btw.

Edit: I came out with 32 degrees C as the final for both. Any chance I can get confirmation on this? Ill wait awhile and if nobody posts Ill mark as solved. Thanks again Ivy, your my hero!

Last edited:

Oh my GOD

Temperature will be 28 C in equilibrium with water and nail.
If you have eqations ready is simple.
Put them L one = P one and find answer for T.
Nails will lose from 40C - 12C= 28C
Water will gain heat from 20C + 8C = 28C also
very simple and time consuming but some people are fast so it is their own negative to be not able to stop and think for a while to grab the answare in the balls

## 1. What is the definition of quantity of heat?

The quantity of heat, also known as heat energy, is a measurement of the total amount of thermal energy in a substance or system. It is measured in units of joules (J) in the International System of Units (SI).

## 2. How is the specific heat of water determined?

The specific heat of water is determined by measuring the amount of heat required to raise the temperature of 1 gram of water by 1 degree Celsius. This value is approximately 4.18 joules per gram-degree Celsius (J/g°C).

## 3. What factors affect the specific heat of a substance?

The specific heat of a substance is affected by factors such as the chemical composition, density, and temperature of the substance. It can also vary depending on the phase of the substance (solid, liquid, or gas).

## 4. How does the specific heat of iron compare to the specific heat of water?

The specific heat of iron is significantly lower than the specific heat of water. This means that it takes less heat energy to raise the temperature of iron compared to water. Iron has a specific heat of approximately 0.45 J/g°C, while water has a specific heat of 4.18 J/g°C.

## 5. How is the quantity of heat calculated for a substance?

The quantity of heat can be calculated using the equation Q = mcΔT, where Q is the quantity of heat, m is the mass of the substance, c is the specific heat, and ΔT is the change in temperature. This equation allows for the determination of the amount of heat energy required to change the temperature of a substance by a certain amount.

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