Table of contents

Word equation

aluminum nitrate + water → nitric acid + aluminum hydroxide

Input interpretation

Al(N + H2O HNO3 + Al(OH)3

Aluminum nitrate water nitric acid aluminum hydroxide

Balanced equation

Balance the chemical equation algebraically: 

Al(NO3)3 + H2O HNO3 + Al(OH)3

Add stoichiometric coefficients,  c1, to the reactants and products:

c1Al(NO3)3 + c2H2O c3 HNO3 + c4Al(OH)3

Set the number of atoms in the reactants equal to the number of atoms in the products for Al, N, O and H:

Al: c1= c4

N: 3c1= c3

O: 9 c1 + c2 = 3c3+ 3c4

H: 2c2= c3+ 3c4

Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set  c1 = 1 and solve the system of equations for the remaining coefficients:

c1 = 1

c2=3

c3=3 

c4=1

Substitute the coefficients into the chemical reaction to obtain the balanced equation:

Answer:

Al(NO3)3 + 3H2O 3 HNO3 + Al(OH)3