5. you have 100 kg of gas of the following composition: ch4 - 30% h2 - 10% n2 - 60% what is the average molecular weight of this gas?

21.8 g/mol

Explanation:

Molecular weight of CH4 = 16g/mol

H2 = 2g/mol

N2 = 28g/mol

(16*30 + 2*10 + 28*60)/100

=2180/100

=21.8g/mol

Answer : To calculate the standard molar enthalpy of complete combustion of liquid ethanol can be done by using the formula given below;



Now, the enthalpies of the elements in their standard state is zero always. 

So the 

Here we can avoid the heat of enthalpy of oxygen,carbon dioxide and water as they exists in their standard states.

So the =