For example for this reaction:

Step 1: $\ce{CO(g) + 2H2(g) -> CH3OH(l)}$

Step 2: $\ce{CH3OH(l) -> CH4(g) + 0.5 O2(g)}$

for step 1, when computing the standard heat of formation

𐤃H = 𐤃H($\ce{CH3OH}$) - 𐤃H($\ce{CO}$)

I don't include hydrogen gas because its "element is in its standard state so 𐤃H=0".

What does it mean by standard state and how would I know ?

  • 1
    $\begingroup$ Please format sentences properly, checking spelling and grammar. $\endgroup$
    – Buck Thorn
    Oct 27, 2022 at 11:08
  • 1
    $\begingroup$ This is the first time I see Phoenician alphabet used in physical chemistry. It's cool and all, but the text should be written from right to left, if you want to go full proto. $\endgroup$
    – andselisk
    Oct 27, 2022 at 12:07


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