# Calculating heat from H2 and O2

• Butterfly_grl
In summary: If you have the amount of hydrogen ( number of moles ) then you can calculate the heat energy. Ok, but let me get this right.. We didn't mention the oxygen because it doesn't have heat of combustion, but if I mix the hydrogen with any element that has heat of combustion I'll just add them to get the final heat of combustion. SO Is that right?Another Question :How can you calculate the temperature when you have the heat energy? I think of course it needs another factor like the "initial temprature" but I don't know...
Butterfly_grl
It is known that Hydrogen and Oxygen when combined can combust of course. So my question is : Can I calculate the heat produced from this combustion if I put a certain amount of hydrogen and oxygen?

Butterfly_grl said:
It is known that Hydrogen and Oxygen when combined can combust of course. So my question is : Can I calculate the heat produced from this combustion if I put a certain amount of hydrogen and oxygen?

You certainly can calculate it. Since all H2/O2 molecules are identical, the same amount of energy will be released each time and so we can just quote a standard value from a textbook. I presume the reaction you have in mind is

2*H2 + O2 --> 2*H2O

which according to http://en.wikipedia.org/wiki/Hydrogen" has an enthalpy of combustion equal to 287 KJ/mol.

If you have a molar ratio different from 2:1 then complete combustion is impossible and the amount of energy you can extract will differ.

Last edited by a moderator:
Google "heat of combustion hydrogen", then multiply that number by the amount of hydrogen you have.

Alewhey said:
If you have a molar ratio different from 2:1 then complete combustion is impossible and the amount of energy you can extract will differ.

I think I understand this part but I've got a couple of questions.

1. When you say "complete combustion is impossible" that doesn't mean there's no combustion, there is but with a less or more amount. Right?

2. if such thing (molar ratio diffrent than 2:1) happened how can I calculate the energy then.

Again could you give me an example.

Thanks alot.

russ_watters said:
Google "heat of combustion hydrogen", then multiply that number by the amount of hydrogen you have.

If I have the amount of hydrogen ( number of moles ) then I can calculate the heat energy. Ok, but let me get this right.. We didn't mention the oxygen because it doesn't have heat of combustion, but if I mix the hydrogen with any element that has heat of combustion I'll just add them to get the final heat of combustion. SO Is that right?

Another Question :

How can you calculate the temperature when you have the heat energy? I think of course it needs another factor like the "initial temprature" but I don't know...

Thanks

## 1. How do you calculate the heat produced from H2 and O2?

To calculate the heat produced from H2 and O2, you can use the formula Q = mCΔT, where Q is the heat, m is the mass of the substance, C is the specific heat capacity, and ΔT is the change in temperature. You will need to know the mass of H2 and O2, as well as their respective specific heat capacities.

## 2. What is the specific heat capacity of H2 and O2?

The specific heat capacity of H2 and O2 can be found in a table of physical properties of gases. The specific heat capacity of H2 is approximately 14.3 J/g°C and the specific heat capacity of O2 is approximately 0.92 J/g°C.

## 3. Can you calculate the heat produced from H2 and O2 at room temperature?

Yes, you can calculate the heat produced from H2 and O2 at room temperature by substituting the mass and specific heat capacity values into the formula Q = mCΔT. Room temperature is typically around 25°C, so ΔT would be 25°C.

## 4. What units are used to measure heat?

Heat is typically measured in joules (J) or calories (cal). One joule is equal to one calorie, so the units can be converted between each other. Some other units that may be used to measure heat include BTUs and kilowatt-hours.

## 5. How does the calculation of heat from H2 and O2 relate to energy production?

The calculation of heat from H2 and O2 is important in energy production because the reaction between these two gases produces a large amount of heat, which can then be harnessed to generate electricity or power other processes. Understanding the amount of heat produced can help in designing more efficient energy production systems.

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