Preparation of insoluble salt and the solubility table

01 Feb Preparation of insoluble salt and the solubility table

Chemistry tuition classes in Miracle Learning Centre are easy to understand and help you in the chemistry tuition application questions. If you do not understand chemistry in school, you must definitely come for chemistry tuition classes at Miracle Learning Centre. Let us learn about the preparation of insoluble salt in this chemistry tuition lesson.

Before we learn about preparation of insoluble salts, we need to learn about the solubility table. The solubility table tells us which salts are soluble in water and which salts are not soluble in water. The first rule states that all nitrates are soluble. That means, zinc nitrate, magnesium nitrate, copper (II) nitrate are all soluble in water.

The second rule states that all sodium, potassium, ammonium salts and Group I salts are soluble in water. That means that sodium nitrate, sodium sulfate, sodium carbonate are soluble in water. Similarly, potassium nitrate, potassium sulfate, potassium carbonate are also soluble in water. A simple way to remember this rule is to remember SPA. They are known as SPA salts.

The third rule states that all sulfates are soluble except lead(II) sulfate, barium sulfate and calcium sulfate. This means that magnesium sulfate is soluble, zinc sulfate is soluble, potassium sulfate is soluble.
The fourth rule states that for chlorides, all chlorides are soluble except silver chloride and lead(II) chloride is insoluble. For bromides, silver bromide and lead(II) bromide are also insoluble. This rule also tells us that magnesium chloride, zinc chloride, barium chloride are all soluble in water. This applies for all the halogens in Group VII.

Rule number five states that all carbonates are insoluble in water except sodium carbonate, potassium carbonate and ammonium carbonate which are the SPA salts. Hence we learn that calcium carbonate, zinc carbonate and magnesium carbonate are insoluble in water.

Rule number six which is the last rule states that all hydroxides are insoluble in water except sodium hydroxide, potassium hydroxide and aqueous ammonia. Barium hydroxide, calcium hydroxide and Group II hydroxides are slightly soluble in water. Group I hydroxides are soluble in water.

From here, we can proceed to learn about the preparation of insoluble salts. Some examples are of insoluble salts includes barium sulfate, lead (II) chloride, silver chloride, calcium sulfate and lead (II) bromide.

To prepare barium sulfate which is an insoluble salt, we need to start with two soluble reagents. Hence, we will use barium nitrate and sulfuric acid to react together to form barium sulfate and nitric acid. This reaction is called precipitation reaction. Barium sulfate which is an insoluble salt is the precipitate that is formed when two solutions are added together. Another example of a precipitation reaction is when silver nitrate reacts with sodium chloride. The product formed will be silver chloride and sodium nitrate. The white precipitate formed is silver chloride.

How does the procedure works? We will add barium nitrate and sulfuric acid together. The precipitate formed is barium sulfate. We filter the mixture of barium sulfate and nitric acid. The residue will be barium sulfate which is what we want to obtain. We will rinse barium sulfate with water and then we dry it using filter paper. Hence, we have completed the process of preparing an insoluble salt called barium sulfate.

Joel, a student at Miracle Learning Centre asked, “Why do we need to learn about preparation of insoluble salts?” Mrs Lew, the teacher at Miracle Learning Centre answered, “The preparation of insoluble salt is very useful to us. This can be used in qualitative analysis to identify what are the substances that are present in a mixture. Precipitation reactions are also used to prepare insoluble salts that we would want to obtain.”

Miracle Learning Centre aims to educate students about how to prepare insoluble salts. Do come to Miracle Learning Centre for more chemistry tuition lessons to learn more about preparation of insoluble salt.

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