Question

Aqueous solutions of lithium sulfate and calcium nitrate are mixed, forming the precipitate calcium sulfate.

Short answer

When lithium sulfate (\(Li_2SO_4\)) and calcium nitrate (\(Ca(NO_3)_2\)) are mixed in an aqueous solution, a precipitation reaction occurs, forming calcium sulfate (\(CaSO_4\)) as a solid precipitate. The balanced chemical equation for this reaction is: \[Li_2SO_4(aq) + Ca(NO_3)_2(aq) \rightarrow CaSO_4(s) + 2LiNO_3(aq)\] The net ionic equation is: \[Ca^{2+}(aq) + SO_4^{2-}(aq) \rightarrow CaSO_4(s)\] Lithium ions (\(Li^+\)) and nitrate ions (\(NO_3^-\)) remain in the solution as spectator ions without participating in the reaction.

Step-by-step solution

Write down the chemical formulas of the given compounds

The chemical formulas of the given compounds are as follows: - Lithium sulfate: \(Li_2SO_4\) - Calcium nitrate: \(Ca(NO_3)_2\) - Calcium sulfate: \(CaSO_4\)

Write down the balanced equation

In order to write the balanced chemical equation, first, identify the possible ions formed when the aqueous solutions are mixed. - Lithium sulfate dissociates into lithium ions \(Li^+\) and sulfate ions \(SO_4^{2-}\). - Calcium nitrate dissociates into calcium ions \(Ca^{2+}\) and nitrate ions \(NO_3^-\). So, initially, the chemical equation will be: \[Li_2SO_4(aq) + Ca(NO_3)_2(aq) \rightarrow CaSO_4 (s) +?\] Now, we will balance the equation: \[Li_2SO_4(aq) + Ca(NO_3)_2(aq) \rightarrow CaSO_4(s) + 2LiNO_3(aq)\] So, the balanced chemical equation is: \[Li_2SO_4(aq) + Ca(NO_3)_2(aq) \rightarrow CaSO_4(s) + 2LiNO_3(aq)\]

Identify the precipitate

As mentioned in the problem, calcium sulfate (\(CaSO_4\)) forms a precipitate. It is insoluble in water, so it forms solid particles that are visible as a precipitate.

Write the net ionic equation

To write the net ionic equation, we first write the full ionic equation by showing all the ions in the aqueous solution: \[2Li^+(aq) + SO_4^{2-}(aq) + Ca^{2+}(aq) + 2NO_3^-(aq) \rightarrow CaSO_4(s) + 2Li^+(aq) + 2NO_3^-(aq)\] Now, we cancel out the spectator ions, which are the ions that do not participate in the chemical reaction. In this case, lithium ions (\(Li^+\)) and nitrate ions (\(NO_3^-\)) are the spectator ions. The net ionic equation for the reaction is: \[Ca^{2+}(aq) + SO_4^{2-}(aq) \rightarrow CaSO_4(s)\]

Interpret the results

The balanced chemical equation and net ionic equation show the reaction that occurs when lithium sulfate and calcium nitrate are mixed in an aqueous solution. Calcium sulfate precipitates out as a solid due to its insolubility in water. On the other hand, lithium ions and nitrate ions remain in the solution as spectator ions without participating in the reaction.

Key concepts

chemical equations

Understanding chemical equations is essential for delving into reactions like precipitation, which occur in myriad chemical processes. A chemical equation provides a symbolic representation of a chemical reaction, mapping out the reactants that interact and the products that are formed.

For instance, when mixing aqueous solutions of lithium sulfate \(Li_2SO_4\) and calcium nitrate \(Ca(NO_3)_2\), we observe the formation of calcium sulfate, a solid precipitate, due to the reaction. The equation \[Li_2SO_4(aq) + Ca(NO_3)_2(aq) \rightarrow CaSO_4(s) + 2LiNO_3(aq)\] is balanced, meaning the number of atoms for each element is the same on both sides of the arrow. These equations are akin to recipes, providing the correct proportions of ingredients (reactants) and final products.

For students, breaking down each component of a chemical equation reveals how different substances come together or separate during chemical reactions. This can enable the prediction of product formation, understanding of reaction conditions, and also help infer reaction mechanisms.

net ionic equations

Net ionic equations streamline chemical reactions by focusing on the particles that directly participate in the formation of the precipitate, eliminating spectator ions, which do not undergo any chemical change. This specialized equation form is insightful when dealing with precipitation reactions, as it highlights the driving forces behind the formation of precipitates.

In the given exercise, the net ionic equation for the reaction between lithium sulfate and calcium nitrate is \[Ca^{2+}(aq) + SO_4^{2-}(aq) \rightarrow CaSO_4(s)\]. Here, we see the calcium ions \(Ca^{2+}\) and sulfate ions \(SO_4^{2-}\) combining to form the insoluble product, calcium sulfate \(CaSO_4\), while lithium \(Li^+\) and nitrate \(NO_3^-\) ions remain dissolved as spectators.

Students should learn to write net ionic equations by first penning down all ions present, then identifying and removing the spectator ions. The left-over ions constitute the net reaction, revealing the essence of the chemical change. Grasping this concept is a stepping stone to understanding how to predict and determine precipitate formation in various reactions.

solubility rules

Solubility rules act as a guiding map for predicting whether a compound will dissolve in water or form a precipitate. The ability to anticipate the solubility of substances is imperative when predicting the outcome of ionic reactions like the one we're studying.

Some key solubility rules relevant to the exercise include the following general trends:

• Most sulfate salts are soluble in water, with exceptions including calcium sulfate \(CaSO_4\), which is slightly soluble and can form precipitates.
• Most nitrates \(NO_3^-\) salts are soluble, meaning they will not form a precipitate in aqueous solutions.

Applying these rules, we infer that calcium sulfate, being an exception to the general solubility of sulfates, forms a precipitate. In contrast, lithium nitrate remains dissolved due to the high solubility of nitrates.

Students must familiarize themselves with these solubility rules as they provide the necessary framework for identifying the solid products in precipitation reactions. Mastering these rules makes it easier to predict reaction outcomes without needing to conduct actual experiments, thus increasing efficiency and understanding in the study of chemistry.