Explanation:
Molar mass
The mass present in one mole of a specific species .
The molar mass of a compound , can easily be calculated as the sum of the all the individual atom multiplied by the number of total atoms .
(a) )hydrogen fluoride, HF
Since ,
Molar mass of of the atoms are -
Hydrogen , H = 1 g/mol
Fluorine, F = 19 g/mol.
Molar mass of HF = ( 1 g/mol ) + ( 19 g/mol ) = 20 g/mol.
(b) ammonia, NH₃
Molar mass of of the atoms are -
nitrogen, N = 14 g/mol
and Hydrogen , H = 1 g/mol
Molar mass of NH₃ = 14 + ( 3 x 1 ) g/mol = 17 g/mol.
(c) nitric acid , HNO₃
Molar mass of of the atoms are -
oxygen , O = 16 g/mol.
Hydrogen , H = 1 g/mol
nitrogen, N = 14 g/mol
Molar mass of HNO₃ = (1 g/mol ) + ( 14 g /mol) + ( 3 x 16 ) = 63 g/mol.
(d)Silver sulfate, Ag₂SO₄
Molar mass of of the atoms are -
silver, Ag = 108 g/mol
sulfur, S = 32 g/mol.
oxygen , O = 16 g/mol.
molar mass of Ag₂SO₄ = ( 2 x 108 g/mol ) + ( 32 g /mol )+ (4 x16 g/mol )
=312 g/mol.
(e )boric acid , B(OH)₃
Molar mass of of the atoms are -
boron , B = 11 g/mol
oxygen , O = 16 g/mol.
Hydrogen , H = 1 g/mol
Molar mass of B(OH)₃ = ( 11 ) + ( 3x16 ) + ( 3 x 1 ) = 62 g/mol.