In a combustion furnace, 2094 standard ft3 per hour
of natural gas (methane) is burned with 6% excess air.
how many standard ft3 of air are drawn from outside
per hour by the fan that supplies the air?

Explanation:

The chemical reaction is as follows.

It is given that 2094 . And, it is known that 1 = 127133

Hence, convert 2094 into as follows.

                  =

As ideal gas equation is PV = nRT. So, calculate the number of moles as follows.

                   n =

                      =

                       = 0.673 mol/sec

According to the stoichiometry of the given reaction, 1 mol of methane reacts with 2 mol of oxygen.

So, 1 mol = 2 mol = 1.346 mol/s

Hence, air required theoretically = = 6.4095 mol/s.

Since, 6% of excess air is being supplied. Therefore, total air supplied will be calculated as follows.

                Total air supplied =

                                              = 6.794 mol/s

Now, calculate the volume using ideal gas law equation as follows.

                            PV = nRT

                           V = 0.166229

Converting calculated volume into as follows.

                  1 = 127133

So,        0.166229 =  

                                        = 21133.191

Thus, we can conclude that 21133.191 of air are drawn from outside  per hour by the fan that supplies the air.

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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