Estimate the standard heat of formation of one of the basic buildin block of life, the amine acid glycine.
(a) NH3 (b) H2O (C) H2O2
D(NÎN)=944; D(H-H)=436; D(OÎO)=498; D(O-O)= 142; D(N-N)=391; D(O-H)=464
To estimate the standard heat of formation of glycine, you need to consider the heat of formation of its basic building blocks. Glycine is an amino acid composed of carbon, hydrogen, nitrogen, and oxygen atoms.
The formula for glycine is NH2CH2COOH. To estimate the heat of formation of glycine, we need to calculate the sum of the heat of formation of each individual component.
1. NH3 (Ammonia): The heat of formation of NH3 is given as D(N≡N) = 944 kJ/mol.
2. H2O (Water): The heat of formation of H2O is given as D(H-H) = 436 kJ/mol.
3. CO2 (Carbon Dioxide): The heat of formation of CO2 is not provided, but we can estimate it using available data. The heat of formation of CO2 is -393.5 kJ/mol.
4. NH2CH2COOH (Glycine): Now, we need to calculate the heat of formation of glycine using the heat of formation of the building blocks.
a) NH2CH2COOH can be divided into two parts: NH2CH2 and COOH.
b) NH2CH2: This part contains one nitrogen atom (N), three hydrogen atoms (H), and two carbon atoms (C).
c) COOH: This part contains one carbon atom (C), two oxygen atoms (O), and one hydrogen atom (H).
d) Summing up the heat of formation of each element:
Heat of formation of NH2CH2 = [1 * D(N≡N)] + [4 * D(H-H)] - [2 * D(C=O)] - [3 * D(C-H)] - [2 * D(C-C)].
Heat of formation of COOH = [1 * D(C=O)] + [1 * D(O≡O)] + [1 * D(O-H)] - [1 * D(C-H)].
5. Add the heat of formation of NH2CH2 and COOH together to get the total heat of formation for glycine.
Please note that the exact heat of formation of glycine may vary depending on the method used for estimation.