Question

M ynt (in g) of nitrogen atoms in 6.14 x 10" molecules of dinitrogen anden 9 2.02g Imor 2204-) -1030 ( IMEL N204-) 16.022x1023 = 9.38 23 x 100 14.01X2 28.02 16*4= 64 Calculate the percent composition by mass of aluminum hydroxide, Al(OH) 34:6% ! anr-2,9x Α1 18 61.5% 3.9% x 3 102% ALY

calculate the percent composition by mass of aluminum hydroxide AL(OH)3

Answer 1

First we will find Molar Mass of Aluminium Hydroxide

Molar Mass of Aluminium Hydroxide Al(OH)3 = (1 x 27) + (3 x 16) + (3 x 1) g/mol

= (27 + 48 + 3) g/mol

= 78 g/mol

Now,

Percentage Composition of Aluminium = (Mass of Aluminium / Molar Mass of Al(OH)3 ) X 100

= (27 / 78) X 100%

= 34.6 %

Percentage Composition of Oxygen = (Mass of Oxygen / Molar Mass of Al(OH)3 ) X 100

= (48 / 78) X 100%

= 61.5 %

Percentage Composition of Hydrogen = (Mass of Hydrogen / Molar Mass of Al(OH)3 ) X 100

= (3 / 78) X 100%

= 3.85 %