Question

Which of the following pairs of aqueous solutions would be most likely to produce a precipitate when mixed? PLEASE SHOW WORK!
a. KCl and Mg(NO3)2 b. Na2S and Cr(NO3)2 c. MgCl2 and Na2SO4 d. KCl and NiBr2

Answer 1

(a)$2KCl+Mg(NO_3)_2 ->MgCl_2+2KNO_3$

Both the compounds in the product side are ionic and is soluble in water.

(b)$Na_2S+Cr(NO_3)_2->2NaNO_3+CrS$

Both the compounds in the product side are ionic and is soluble in water.

(c)$MgCl_2+Na_2SO_4->MgSO_4+2NaCl$

So,MgSO₄ forma ppt.

(d)$2KCl+NiBr_2->NiCl_2+2KBr$

Both the compounds in the product side are ionic and is soluble in water.

Precipitate is formed in case of (c).