# A level chemistry HELP

I know the answer (D) just not how you get to it. I know the equation but damn whats all this organic talk. It doesn't give you the desired mass either

Which chemical process is the most sustainable in terms of atom economy of the organic product?
(a) CO2 + 3H2 -> CH3OH + H2O
(b) CH3CH2OH + NaCl + H2SO4 -> CH3CH2Cl + NaHSO4 + H2O
(c) CH3CH2Br + NaOH -> CH3CH2OH + NaBr
(d) CH3CH2CH2CH2OH -> CH3CH2CH=CH2 + H2O
the organic product is going to be the one with the carbons and hydrogens and such. so in this case:
(a) CH3OH
(b) CH3CH2Cl
(c) CH3CH2OH
(d) CH3CH2CH=CH2
since it's a multiple choice, i'll show you a shortcut!

atom economy has the equation 'Mr of desired product/ sum of Mr of all products x 100' and so you're gonna be looking for a bigger number on top to maximise the percentage. in this case, you don’t need the desired mass, just Mr. already, looking at (d) the organic product is the bigger one of the two products, so you'll get a high percentage. you dont need to calculate the other ones once you spot this, as (a) has a relatively small organic product, (b) has many other products which decrease atom economy, and (c) is similar to (b). for d, you get:
(12 x 4) + (1 x 8) / (12 x 4) + (1 x 8) + 18 then x100 to get 75.68%, the highest atom economy.
Original post by MinMin25
the organic product is going to be the one with the carbons and hydrogens and such. so in this case:
(a) CH3OH
(b) CH3CH2Cl
(c) CH3CH2OH
(d) CH3CH2CH=CH2
since it's a multiple choice, i'll show you a shortcut!

atom economy has the equation 'Mr of desired product/ sum of Mr of all products x 100' and so you're gonna be looking for a bigger number on top to maximise the percentage. in this case, you don’t need the desired mass, just Mr. already, looking at (d) the organic product is the bigger one of the two products, so you'll get a high percentage. you dont need to calculate the other ones once you spot this, as (a) has a relatively small organic product, (b) has many other products which decrease atom economy, and (c) is similar to (b). for d, you get:
(12 x 4) + (1 x 8) / (12 x 4) + (1 x 8) + 18 then x100 to get 75.68%, the highest atom economy.

THANK YOU. I was struggling with the wording. By sustainable it means the atom economy is larger correct? With the equation you wrote for d why did you add 18 on the end. Sorry for asking so much ://////
Original post by biob0ss
THANK YOU. I was struggling with the wording. By sustainable it means the atom economy is larger correct? With the equation you wrote for d why did you add 18 on the end. Sorry for asking so much ://////

The 18 is the Mr of H20, which is required to calculate the total Mr of all the products.
Original post by AB27
The 18 is the Mr of H20, which is required to calculate the total Mr of all the products

kisses u
From an organic product does it mean by an compounds having a double bond