Question

Help with this chemistry problem...idk why this is wrong...

Answer 1

@amistre64 @nincompoop

Answer 2

which of those are FORMATION reactions, and which of those use the reactants in their STANDARD states?

Answer 3

The first one is the only one in the standard state? Not sure

Answer 4

wait...the last one too...right?

Answer 5

the last reaction isn't a formation reaction.

Answer 6

look at each reaction carefully. In order for \(\Delta H_{rxn}\) to equal \(\Delta H_f\), the reaction has to be a formation reaction, and the reactants and product have to be in their standard states

Answer 7

formation...as in it forms a molecule?

Answer 8

I thought it would be the first 3, but that was wrong

Answer 9

formation reactions have to be synthesis reactions where the reactants are ELEMENTS, not other MOLECULES, and every substance has to be in its standard state

Answer 10

so the first one would not work because you have H2?

Answer 11

hydrogen is a diatomic element, so \(H_2\) is the proper formula for hydrogen gas. The first choice is a formation reaction

Answer 12

Ok, so then you can do 1/2 F2 for example. Because F2 is the proper formula for flourine gas?

Answer 13

cant*

Answer 14

you can, because the coefficients in front don't change the formula of the reactants, they just change how many of them you use in the reaction

Answer 15

ok, so that means that the first two can be formation reactions, the third one cannot because it says that F2 is a liquid, the 4th one can be, and the 5th one can also be one?...I tried that but it is wrong.

Answer 16

Sorry, I just really dont get this that well