You can use the mole ratios given by the coefficients in the balanced chemical equation. The coefficients are the smallest whole-number number of moles.
Aluminum hydroxide is insoluble in water, while calcium sulfate is only marginally soluble.
Al2(SO4)3(aq) + 3Ca(OH)2(aq) --> 2Al(OH)3(s) + 3CaSO4(s)
1 mol ................. 3 moles ............... 2 moles ......... 3 moles
0.725 mol
0.725 mol ......... 3(0.725) mol ........ 2(0.725) mol ..3(0.725) mol
Al2(SO4)3(aq) + 3Ca(OH)2(aq) --> 2Al(OH)3(s) + 3CaSO4(s)
1 mol ................. 3 moles ............... 2 moles ......... 3 moles
........ .................. 0.774 mol
0.774 / 3 mol ..... 0.774 mol .......... 2/3(0.774)mol.. 0.774 mol
