Chemistry Past Questions | JAMB, WAEC, NECO and Post UTME Past Questions

\(\mathrm{H_2SO_3}\)

\((+1 \times 2) + \text{S} + (-2 \times 3) = 0\)

\(2 + \text{S} - 6 = 0\)

\(-4 + \text{S} = 0\)

TO GET S ADD +4 TO THE BOTH SIDES:

\(-4 + 4 + \text{S} = 0 + 4\)

\(\text{S} = +4\)

Al_(s) → Al³⁺_(aq) + 3e^- -------(i)
Cu²⁺_(aq) + 2e^- → Cu_(s) -------(ii)

To balance the electrons, multiply equation (i) by 2 and equation (ii) by 3 and then add the resulting equations

2Al_(s) → 2Al³⁺_(aq) + 3e^-
3Cu²⁺_(aq) + 6e^- → 3Cu_(s)
2Al_(s) + 3Cu²⁺_(aq) → 3Cu_(s) + 2Al³⁺_(aq)

A peptide is a molecule composed of two or more amino acids. The bond that holds together the two amino acids is a peptide bond, or a covalent chemical bond between two compounds (in this case, two amino acids). It occurs when the carboxylic group of one molecule reacts with the amino group of the other molecule, linking the two molecules and releasing a water molecule.

Long chain polypeptides can be formed by linking many amino acids to each other via peptide bonds. The amide bond can only be broken by amide hydrolysis, where the bonds are cleaved with the addition of a water molecule. The peptide bonds of proteins are metastable, and will break spontaneously in a slow process. Living organisms have enzymes which are capable of both forming and breaking peptide bonds .