Question

In a gaseous mixture of 2 mol of CO2 , 1 mol of H2 and 2mol of He are present than determine mole % of CO2.

Answer 1

2 mole of co2 = Na ×2 ( Na = avagadro). 1 mole of H2 = Na ×1. 2 mole of he. = Na × 2 total Na = 5 Na. ,. 2Na/5Na ×100 = 40%

Answer 2

CH4 + 2O2 → CO2 +2 H2O this is the reaction of combustion of methane.

C + O2 → CO2 ∆H1 = -393 Kj/mol

H2 + 1/2O2→ H2O; ∆ H2 = 286.2 Kj/mol  

C + 2H2 → CH4 ; ∆H3 = -74.8 kj/mol  

CH4 → C + 2H2 , ∆H3' = 74.8  

C + O2 → CO2 ∆ H1 = -393  

2( H2 + 1/2O2 → H2O ; ∆H2 = 2× 286.2  

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add this reactions,  

CH4 + 2O2 → CO2 +2H2O  

∆H =( 74.6 -393 +2×286.2 ) Kj/mol  

=254 Kj/mol