Which of the following pairs of aqueous solutions will form a precipitate when mixed? Ca(C2H3O2)2 + Na2SO4 KOH + Na2S KNO3 + LiOH (NH4)2SO4 + KI None of the above solution pairs will produce a precipitate.

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.