Question

1. Write a balanced chemical equation for each double replacement reaction that occurs. Note: Compounds with Na+, K+, and/or NO3− are soluble.

2. Why was there no reaction in some of the wells? (See Introduction.)
3. How could you tell a Ca(NO3)2 solution from a Zn(NO3)2 solution?
4. How could you tell a Cu(NO3)2 solution from a Ni(NO3)2 solution?

Answer 1

To predict products and write balanced equations for double-replacement reactions, solubility rules are essential. For instance, AgNO3 and CaCl2 react to form insoluble AgCl. Distinguishing nitrate solutions can involve testing for color change, precipitate, or electrical conductivity.

Step-by-step explanation:

The process of predicting products and writing balanced chemical equations for double-replacement reactions requires understanding of the solubility rules. An example would be the reaction of Pb(NO3)2 with KBr. Since both compounds are soluble, and their respective exchange products KNO3 and PbBr2 are also soluble, no reaction is expected. On the other hand, a reaction such as the combination of AgNO3 and CaCl2 leads to the formation of insoluble AgCl, which can be represented by the following equations:

• Complete chemical equation: AgNO3(aq) + CaCl2(aq) → AgCl(s) + Ca(NO3)2(aq)
• Complete ionic equation: Ag+(aq) + NO3-(aq) + Ca2+(aq) + 2Cl-(aq) → AgCl(s) + Ca2+(aq) + 2NO3-(aq)
• Net ionic equation: Ag+(aq) + Cl-(aq) → AgCl(s)

To distinguish between different nitrate solutions such as Ca(NO3)2 and Zn(NO3)2 or Cu(NO3)2 and Ni(NO3)2, one could perform tests based on color change, precipitate formation, or differences in electrical conductivity when dissolved in water.