Question

determine the molar mass of al₂(so₄)₃·5 h₂o(s). provide an answer to two decimal places.

Explanation:

Step1: Identify atomic masses

Atomic mass of Al: 26.98 g/mol, S: 32.07 g/mol, O: 16.00 g/mol, H: 1.01 g/mol

Step2: Calculate molar - mass of $Al_2(SO_4)_3$

For $Al_2(SO_4)_3$:
Number of Al atoms = 2, mass contribution of Al = 2×26.98 = 53.96 g/mol
Number of S atoms = 3, mass contribution of S = 3×32.07 = 96.21 g/mol
Number of O atoms = 12, mass contribution of O = 12×16.00 = 192.00 g/mol
Molar - mass of $Al_2(SO_4)_3$ = 53.96+96.21 + 192.00=342.17 g/mol

Step3: Calculate molar - mass of $5H_2O$

Number of H atoms in $5H_2O$ = 10, mass contribution of H = 10×1.01 = 10.10 g/mol
Number of O atoms in $5H_2O$ = 5, mass contribution of O = 5×16.00 = 80.00 g/mol
Molar - mass of $5H_2O$ = 10.10+80.00 = 90.10 g/mol

Step4: Calculate molar - mass of $Al_2(SO_4)_3\cdot5H_2O$

Molar - mass of $Al_2(SO_4)_3\cdot5H_2O$ = Molar - mass of $Al_2(SO_4)_3$+Molar - mass of $5H_2O$
= 342.17+90.10 = 432.27 g/mol

Answer:

432.27 g/mol