Balance the following equation. then determine the mole ratio of ca(oh)2: al(oh)3.
al2(so4)3 + ca(oh)2 al(oh)3 + caso4?
a.)2: 3
b.)3: 2
c.)1: 2
d.)3: 3
e.)1: 1

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

Well technically there are two correct answers b and d. but for you its probably b in general.good day sir/ma'am : ) (i know not gender)

Do you have any options?