Question

6. What is the difference between equivalent mass and molar mass? 7. A triprotic acid has the molecular formula H2CH3O7. a. What is the molar mass of this acid? 192. 1235 almal b. What is the value of the equivalent mass for this acid?

Answer 1

6. The molar mass of the chemical substance is defined as follows, the sum of total mass of the all elemental atoms in a one mole of the given chemical substance.

For example, the molar mass of NaOH is 40.0 g / mol

The equivalent mass of the chemical substance is defined as follows, the molar mass of the chemical substance is divided by the valency or basicity of an acid or acidity of a base or no. of electrons transfer in a redox reaction.

For example, the equivalent mass of sulfuric acid = (98.0 g / mol) / (2)

                                                                                          = 49.0

The basicity of sulfuric acid is 2.

7. (a) Molar mass of H₃C₆H₅O₇ is calculated as follows,

The molar mass of H₃C₆H₅O₇ = (8*1.00784) + (6*12.0107) + (7*15.999)

                                                         = 192.1199 g / mol

(b) The basicity of the triprotic acid = 3

The equivalent mass = (192.1199 g / mol) / (3)

                                       = 64.040 gram equivalent