# really really really hard help

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#1
Please someone whos smart out there has to be able to just work this out simply someone sow me how its done

super hard reaction
:

CO2 (g) + 2 H2O (l) → CH4 (g) + 2 O2 (g) DH = 890 kJ

a)
Is this an endothermic or an exothermic reaction? Briefly justify your answer.

b)
Calculate the energy produced (or absorbed) by 3.0 mol of CO2.

Calculate the energy produced (or absorbed) by 27.0 g of H2O
0
7 years ago
#2
(Original post by girlslovebarbie)
Please someone whos smart out there has to be able to just work this out simply someone sow me how its done

super hard reaction
:

CO2 (g) + 2 H2O (l) → CH4 (g) + 2 O2 (g) DH = 890 kJ

a)
Is this an endothermic or an exothermic reaction? Briefly justify your answer.

b)
Calculate the energy produced (or absorbed) by 3.0 mol of CO2.

Calculate the energy produced (or absorbed) by 27.0 g of H2O
a) write the reaction in reverse and put a name to the compounds. What kind of reaction must it be?

or (even easier) look at the sign of the enthalpy change ...
0
7 years ago
#3
burning methane is an exothermic reaction, and the equation is the complete reverse. look at the enthalpy value when it's positive its endothermic because the products have higher energy than the reactants and vice versa
0
#4
(Original post by Chris654)
burning methane is an exothermic reaction, and the equation is the complete reverse. look at the enthalpy value when it's positive its endothermic because the products have higher energy than the reactants and vice versa
so its an endothermic reaction because the valve is positive
0
7 years ago
#5
(Original post by girlslovebarbie)
so its an endothermic reaction because the valve is positive
Yes.
0
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