Alculate the standard enthalpy of formation of ethanoic acid given that the standard enthalpy of combustion for carbon is –394 kj mol-1 , hydrogen is –286 kj mol-1 and ethanoic acid is –876 kj mol-

The standard enthalpy of formation of ethanoic acid is -484 kJ/mol.

Explanation:

...[1]

..[2]

..[3]

The standard enthalpy of formation of ethanoic acid :

..[4]

Using Hess's law to calculate :

2 × [1] + 2 × [2] - [3] = [4]

The standard enthalpy of formation of ethanoic acid is -484 kJ/mol.

We have to know the type of reaction involves in building a large protein from amino acid.

The reaction involves is condensation reaction.

Protein is made up of amino acids. Amino acid is the building block of proteins. Amino acids combine by condensation reaction and forms  polypeptide linkages (-CONH-) after loss of small molecules like water.

Amino acid contains an amine group (-NH₂) and one carboxylic acid (-COOH) group. When one amino acid reacts with other amino acid, they lose water molecule and form amide through peptide linkage formation.

If two amino acids combine, then monopeptide is formed while three amino acids form two peptides.