Which two solutions have similar solubilities at 40°c? na2so4 and nacl na2haso4 and nacl na2haso4 and na2so4 ba(no3)2 and ce2(so4)3 • 9h2o

The correct answer is option C i.e. Na2HAsO4 and Na2SO4 Ba(NO3)2 

Refer to the graph attached below which shows how the solubility of a mixture changes with temperature variation.

As you can see in the graph at 40 °C, both Na2HAsO4 and Na2SO4 Ba(NO3)2  have same solubility coefficients. Thus, the answer is Na2HAsO4 and Na2SO4 Ba(NO3)2 

It shows that the experiment is designed properly.

Ithink it’s one of those things that you put the object on