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Rules for Predictions of Double Replacement Reaction

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What are the general characteristics that help you identify individual replacement reactions? According to solubility rules, NaOH and FeCl2 should be soluble. If we assume that a double replacement reaction can occur, we must consider the possible products that would be NaCl and Fe(OH)2. NaCl is soluble, but Fe(OH)2 is not according to solubility rules. Therefore, a reaction would occur and Fe(OH)2(s) would precipitate the solution. The balanced chemical equation is A single replacement reaction is a chemical reaction in which one element is replaced by another element in a compound, creating a new element and compound as products. For example, the net ion equation shows the formation of the insoluble, liquid or gaseous precipitate that forms as a result of the reaction. Hope this helped! Chemical reactivity trends are easy to predict when anions are replaced in simple ionic compounds – just use their relative positions in the periodic table. However, when replacing cations, the trends are not so simple. This is partly because there are so many elements that can form cations; An element in a column of the periodic table may or may not replace another element nearby. A list called a series of activities does the same thing as the periodic table for halogens: it lists the elements that replace the elements below in individual replacement reactions. A simple series of activities is presented below. is an example of a single replacement reaction. The hydrogen atoms in HCl are replaced by Zn atoms, creating a new element – hydrogen.

Another example of a single replacement reaction is A double replacement reaction occurs when parts of two ionic compounds are exchanged, resulting in two new compounds. A characteristic of a double replacement equation is that there are two compounds as reactants and two different compounds as products. There are two equivalent ways of thinking about a double replacement equation: either cations are exchanged or anions are exchanged. (You cannot exchange the two; You`d end up with the same substances you started with.) Both perspectives should allow you to predict the right products, provided you associate a cation with an anion and not a cation with a cation or anion with an anion. Assuming each single replacement reaction occurs, predict the products and write down each balanced chemical equation. A chemical reaction in which parts of two ionic compounds are exchanged. A chemical reaction in which one element is replaced by another element in a compound. List of elements that replace lower elements in single substitution reactions. Take a look at the graph of the double replacement reaction. The rules are followed in the correct order. First, let`s look at $ce{KNO3}$.

The first rule is that alkali metal salts are soluble. Potassium is an alkali metal, so potassium nitrate is soluble. The second product is $ce{Pb(OH)2}$. If you look at the rules, none of them apply until Rule 5, which says hydroxides are insoluble. Therefore, lead hydroxide is insoluble. Not all proposed single replacement reactions occur between two given reactants. This is most easily demonstrated with fluorine, chlorine, bromine and iodine. Together, these elements are called halogens and are located in the penultimate column of the periodic table (see Figure 4.1 « Halogen in the periodic table »). The elements at the top of the column replace the elements below in the periodic table, but not vice versa.

Thus, the reaction represented by the use of the series of activities is similar to the use of the positions of the halogens in the periodic table. A higher element replaces a lower element in compounds that undergo a single replacement reaction. Elements do not replace elements above them in compounds. Prediction of the products of this double replacement equation: BaCl2 + Na2SO4 →? Some double replacement reactions are obvious because you can see a solid precipitate of the solution. To assess whether double replacement reactions occur, we need to know what types of ionic compounds form precipitates. To do this, we use solubility rules, which are general statements that predict which ionic compounds dissolve (are soluble) and which are not (insoluble or insoluble). Table 4.1 « Some useful solubility rules » lists some general solubility rules. We must consider each ionic compound (both reactants and possible products) in light of the solubility rules in Table 4.1 « Some useful solubility rules ».

If a compound is soluble, we use the label (aq) with it, which indicates that it is dissolving. If a compound is insoluble, we use the label(s) and assume that it will precipitate solution. If everything is soluble, no reaction is expected. For example, consider the possible double replacement reaction between Na2SO4 and SrCl2. The solubility rules state that all ionic sodium compounds are soluble and all ionic chloride compounds are soluble, with the exception of Ag+, Hg22+ and Pb2+, which are not considered here. Therefore, both Na2SO4 and SrCl2 are soluble. Possible dual replacement reaction products are NaCl and SrSO4. Are they soluble? NaCl is (according to the same rule we just mentioned), but what about SrSO4? Sulfate ion compounds are generally soluble, but Sr2+ is an exception: we expect it to be insoluble – a precipitate. Therefore, we expect a reaction to occur, and the balanced chemical equation would be a solid fall of the solution into a precipitation reaction. 7.

Use the periodic table or series of activities to predict whether each replacement reaction will occur and, if so, write a balanced chemical equation. Predicting whether a double replacement reaction will occur is slightly more difficult than predicting a single replacement reaction.