Question

(a) Distinguish between molecular mass and molar mass.

(b) Give an example of (i) diatomic, and (ii) triatomic molecule of compounds.​

Answer 1

Answer:

a)Often, people use the terms mass and weight interchangeably. Despite not being technically correct, it doesn't affect calculations. Molar mass is the mass of a mole of molecules, measured in grams or kilograms per mole. In other words, the molar mass of a compound tells you the mass of one mole of that substance.

For example, water has two hydrogen atoms and one oxygen atom. As per the periodic table, the atomic weight of hydrogen is 1 gram, and the atomic weight of oxygen is 16 grams. To calculate the molecular weight of one water molecule, you add (2 x 1) + 16 = 18 grams. The total molar mass of water is 18 grams per mole.

Molecular Weight

Molecular weight is the mass of one molecule, measured in atomic mass units (amu). For example, water has two hydrogen atoms and one oxygen atom. As above, the atomic weight of hydrogen is 1 gram, and the atomic weight of oxygen is 16 grams. To calculate the molecular weight of one water molecule, you add (2 x 1) + 16 = 18 grams. The total molecular weight of water is 18 grams.

b)(i) O2,li2,NaCl,etc

(ii)h2o,co2,etc