Enthalpy reaction?

Question

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Answer 1

I'm only going to get you started on this...Just think of it as a puzzle. You need to combine the various equations given so that when you add them up, you get the equation you are after. Remember that when you multiply an equation by 2, you also multiply the delta H by two, and that when you reverse an equation, you change the sign of delta H.

So, take equation A and reverse it to get B2O3 on the right side (Change the sign of its delta H.).

Equation B has 2 B on the left, but you need 4 B, so multiply that equation (and its delta H) by 2.

Use the other equations to add or get rid of things you don't want...You just need to be able to add everything together to get the equation and delta H that you are after...