00:01
Hello students welcome here in this question we have given that a methane is burning so here it is burning with air so we it will give we know that it is a combustion reaction so it is at 100 degrees celsius and air is at 25 degrees celsius so a furnace with furnace with q is heat capacity is equal to zero having, we have to calculate the out temperature.
00:34
So this is in temperature, this one is out temperature, so we have to calculate out.
00:40
So water going outside, carbon dioxide, oxygen gas and h2o gas and also nitrogen gas is outing here.
00:51
And here it is, um, air is present, oxygen and nitrogen is present.
00:57
So oxygen is 0 .21 and nitrogen is 0 .79 that is equal totally 1 % okay.
01:05
So here we have to calculate the adiabetic flame temperature.
01:10
So we will see adiabatic flame temperature is equal to flame temperature equal to some of the number of and heat capacity of out and number of moles of out is minus here it is number of number of moles in heat capacity in plus and number of in number of moles in that is equal to q okay so here we have q is equal to zero we had to calculate the number of of the number of the number of moles inner, what are the number of moles inner, so inside water there, methane and air.
02:05
So for air we can, we do not, we do not calculate because heat of formation for oxygen is equal to zero, heat of formation of nitrogen is equal to zero.
02:21
So we will calculate only for air.
02:24
So how many moles of air is inner and how many moles of air is outside? so the air number of moles of oxygen in this reaction is 2 moles.
02:36
So 100 % excess, that's why we will take this as 4 moles.
02:41
And nitrogen is given as 2 moles.
02:45
Totally there are 4 moles and given is 0 .79 divided by 0 .21 that is equal to 15 .0 .0 .0 .1 that is equal to 15 .0 .0 .0.
02:54
So number of moles of air in is equal to 15 .04 plus 4 moles, that is equal to 19 .04.
03:06
And number of moles out is equal to air.
03:11
So number of moles of air out is equal to 2 moles is consumed in this reaction.
03:19
So that is 15 .z4 and oxygen 2 moles.
03:23
So that is equal to 17 .04 moles out.
03:28
Okay? number of moles outed.
03:30
So here we will see only out only, we will take here the out one only.
03:37
So here the number of delta h of h for methane we will calculate.
03:46
So methane at 100 degrees celsius is equal to delta.
03:53
Formation of methane plus modulus t is 100 degrees to so it is 25 degrees to 100 degrees so it is a t plus a b t square um a plus b t sorry it is a plus b t sorry it is a d t so this one is for all the all the given components so we are in in components we are calculating here the number of moles of c h4 is n one only and c o too also one mole number of c o two is one mole and number of h2 is two moles because we know the equation c h4 plus o two gives rise to c o two plus h2o.
04:55
So here 2 moles and it is 2 moles.
04:58
So in water taking in only, ch4 only and out is co2 and h2o.
05:06
So we will see only for these three only because for oxygen and nitrogen, delta h is 0.
05:13
So the total heat of energy, heat energy is zero.
05:18
So we are taking only for these three only.
05:23
And co2 and h2o.
05:27
Okay, so here for h2o, a is equal to, for ch4, a is equal to, it is 34 .31 multiplied by 10 power minus 3 and b multiplied by 10 power minus 5 and c is equal to 0.
05:48
0 .m.
05:49
Multiplied by 10 power minus 8 and d is equal to minus 11 multiplied by 10 power minus 12.
05:56
So all these values are substituted in this formula, delta hf0 for co2 minus this one is 74 .85 kilojoules per mole.
06:12
So all these values are substituted in this small, in this equation.
06:16
So ch4 is equal to we will get minus 72 .019.
06:26
So kilojoules per mode.
06:28
Okay.
06:29
So this is for temperature co2 and for delta h for h co2 is equal to methane we calculate.
06:40
Now we are calculating for co2 out one.
06:44
So only in one we have seen...
