U need to do it in cronological order
I think so, <span> how much of all chemistry is to do with numbers? A lot! So being good at mathematics makes a huge aspect of chemistry so much easier but if you aren't mathematical then you can work at it and become reasonably proficient at it.</span>
Answer : The energy produced from the combustion of 5 mole
is 
Solution : Given,
Released energy = 803 KJ
The balanced combustion reaction is,

As per the question,
1 mole of
releases energy = 803 KJ
5 mole of
produced energy = 
Therefore, the energy produced from the combustion of 5 mole
is 
Hey there!:
2 Al(NO)₃+ 3 H₂SO₄ → 1 Al₂O₁₂S₃+ 6 HNO₃
Reagents : Al(NO₃)₃ and H₂SO₄
Products : Al₂O₁₂S₃ and HNO₃
Coefficients : 2 , 3 , 1 and 6
Hope this helps!