# Calorimeter and heat, units question

• fluidistic
In summary, the conversation is about a lab report due next week that involves a formula for specific heat of a metal. The speaker is stuck on the last part and is unsure of the units for c. They mention a website with a similar formula and ask for help in understanding the use of c in the formula.

Gold Member

## Homework Statement

I have a lab report due next week and I'm almost done with it. However I'm totally stuck on the last part where it is wrote in a description of the experience : $$c=\frac{(m+M_e)(T_f'-T'_i)}{m(T_c-T_f)}$$ where $$c$$ is the specific heat of a metal. If I work out the units in the formula, I end up with $$c$$ has no units! It must have units of $$\frac{cal}{g \cdot K}}$$! But I don't know how to make this appear!
The only thing I imagine that can save me is that the $$c$$ above is equivalent to one with units, but I don't know how to justify this. Clearly it makes no sense at all to me.
I'd be very grateful if you could help me. (I'd be so glad to finish the report as soon as possible so that I can study vector analysis...)

I think you need a C of the calorimeter metal on the top.

mgb_phys said:
I think you need a C of the calorimeter metal on the top.

Sorry I don't understand what you mean.
This formula also appear in some websites, like http://www.sc.ehu.es/sbweb/fisica/estadistica/otros/calorimetro/calorimetro.htm (In Spanish. Where it says
El calor específico desconocido del será por tanto...
)
In my formula $$M_e$$ is the mass of water to which the calorimeter is equivalent to.

## 1. What is a calorimeter and how does it work?

A calorimeter is a device used to measure the amount of heat released or absorbed during a chemical or physical process. It works by surrounding the reaction or substance with a known amount of water and measuring the change in temperature of the water to determine the amount of heat transferred.

## 2. What are the units of measurement used for heat and energy?

The commonly used units for heat and energy are Joules (J) and calories (cal). However, in some cases, other units such as British Thermal Unit (BTU) or Electron Volt (eV) may also be used.

## 3. How is the specific heat capacity of a substance determined?

The specific heat capacity of a substance is determined by measuring the amount of heat required to raise the temperature of a known mass of the substance by 1 degree Celsius or Kelvin. The equation used is q = mCΔT, where q is the heat absorbed, m is the mass of the substance, C is the specific heat capacity, and ΔT is the change in temperature.

## 4. Can a calorimeter be used to measure the energy content of food?

Yes, a calorimeter can be used to measure the energy content of food by burning a sample of the food and measuring the temperature change of the water surrounding the reaction. This value can then be used to calculate the energy content of the food in calories or Joules.

## 5. How does the heat of fusion and heat of vaporization relate to a substance's phase change?

The heat of fusion and heat of vaporization are the amounts of heat required to change the phase of a substance from solid to liquid and liquid to gas, respectively. These values are specific to each substance and are related to the strength of intermolecular forces and the distance between particles. During a phase change, the temperature remains constant until all of the substance has changed phase.