Other Double-Replacement Reactions

Write the net ionic equation for any reaction that would occur if solutions of sodium chloride and potassium nitrate are combined. 

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As the solutions are mixed, positive A and C ions exist in solution, as do negative B and D ions, and these oppositely charged ions attract each other. A reaction takes place if a compound forms that removes ions from solution. Products that remove ions from solution in a double-replacement reaction are a precipitate, a gas, or a slightly ionized material, such as water. 

Double Replacement Reaction a reaction between two compounds in which elements or ions replace each other Effluent discharge from a pipe or another source, associated with water quality... 

At heart, neutralization reactions in which the base contains a hydroxide ion are simple doublereplacement reactions of the formHA-l-B0H-> BA-HH2O(in other words, an acid reacts with a base to form a salt and water). You re asked to write a number of such reactions in this chapter, so be sure to review double replacement reactions and balancing equations in Chapter 8 before you delve into the new and exciting world of neutralization. 

In this generic equation, A and B represent positively charged ions (cations), and X and Y represent negatively charged ions (anions). You can see that the anions have switched places and are now bonded to the other cations in the reaction. In other words, X replaces Y and Y replaces X—a double replacement. More simply, you might say that the positive and negative ions of two compounds switch places. The reaction between calcium hydroxide and hydrochloric acid is a double-replacement reaction. 

An oxidation-reduction (redox) reaction is any chemical reaction in which electrons are transferred from one atom to another. Most chemical reachons other than double replacement reactions are oxidation-reduction reactions. 

A double replacement reaction occurs when two ionic compounds react in an aqueous solution, and an ion from one compound replaces the similar ion from the other compound. The general format for a double reaction is ... 

The term metathesis literally means to transpose. The term double replacement is often used to describe these reactions because the cations switch places with each other. These are chemical reactions that involve an exchange of positive ions between two compounds and that generally take place between two ionic compounds in an aqueous solution. The driving force that causes these reactions to occur is a decrease in the number of ions from the reactants to products. This will occur when a stable product forms from the ionic reactants. The three types of stable products that can form are a precipitate (or an insoluble solid), a gas (gaseous materials will bubble out of the solutions and leave the reaction mixture), or a stable molecule (a weak electrolyte, or nonelectrolyte, such as water). A general equation for a double-replacement reaction is... 

A double-replacement reaction, on the other hand, involves two compounds undergoing a "change of partners." Two compounds react by exchanging atoms to produce two new compoimds ... 

A reaction similar to the one between vinegar and baking soda occurs when you combine any acidic solution and sodium hydrogen carbonate. In all cases, two reactions must occur almost simultaneously in the solution to produce the carbon dioxide gas. One of these is a double-replacement reaction and the other is a decomposition reaction. 

For example, when you dissolve sodium hydrogen carbonate in hydrochloric acid, a gas-producing double-replacement reaction occurs. The hydrogen in the hydrochloric acid and the sodium in the sodium hydrogen carbonate replace each other. 

As mentioned previously, gas-phase H/D exchange reactions are a form of ion/mole-cule reaction in which an analyte ion reacts with a neutral deuterated molecule within the confines of an ion-trap or ion-drift tube. The product of the reaction is a covalent exchange of hydrogen for deuterium in what amounts to a double replacement reaction that is expected to proceed through a stable ion-molecule complex. Like other organic reactions, the extent of gas-phase H/D exchange reactions depends on the number density of molecules of each reactant species present and the time during which they are allowed to react. 

Double-substitution or double-replacement reactions, also called double-decomposition reactions or metathesis reactions involve two ionic compounds, most often in aqueous solution. In this type of reaction, the cations simply swap anions during the algorithm, a similar process that in the previous reaction happens, the difference is that in this reaction both of the selected compounds are decomposed and the resulting elements are combined between each other (AB - - CD CB + AD). The pseudocode for the double-substitution reaction procedure is as follows ... 

Write equations for the following double-replacement reaction in total ionic and net ionic forms. Note that barium sulfate (BaS04) does not dissolve in water and should not be written in dissociated form. All other compounds are ionic and soluble in water. 

Different acids have different properties that make some more practical than others for specific uses. However, all acids have certain properties in common. Two of these were mentioned earlier—all acids taste sour and produce H30 ions when dissolved in water. In addition, all acids undergo characteristic double-replacement reactions with solid oxides, hydroxides, carbonates, and bicarbonates (see > Figure 9.2). 

When solutions of two compounds are mixed, a positive ion from one compound may combine with the negative ion from the other compound to form a solid compound that settles to the bottom. The solid is a precipitate the reaction is a precipitation reaction. In the equation for a precipitation reaction, ions of the two reactants appear to change partners. The equation, and sometimes the reaction itself, is a double-replacement equation or a double-replacement reaction. The general equation, with bridges to show the rearrangement of ions, is... 

FIGURE 8.6 In a double replacement reaction, the positive ions in the reactants replace each other. 

Surely these equations satisfy the requirements for the status of law-like propositions. They describe what happens in all like cases of double replacement reactions, that is they apply generally ceteris paribus, to instances or samples of these material stuffs. Other things being equal clauses are more or less explicitly tacked on. For instance, in the later stages of the universe the Hubble expansion will open up such great distances between the surviving ions that no chemical reactions will occur. The ions will be there, but no products will come to be. 

The reactions of hydrogen and oxygen to form water and carbon and oxygen to yield carbon dioxide are examples of combination reactions. A combination or synthesis reaction results when two or more substances unite to form a compound. Many other types of reactions exist. Three other common types of reactions are decomposition, single replacement, and double replacement. 

There are two methods for the preparation of Cu-Ag double metal powder by replacement reaction. One is to react nano copper with silver nitrate solution directly in the existence of polymer protecting agent to produce Cu-Ag double metal powder, which, by TEM determination, appears usually in the form of twigs. In the other method, an Ag(NH i) + solution is used to replace the AgNOj solution to take part in the replacement reaction, and with the other conditions being the same as those in the former method, sphere particles can normally be obtained. The present study is aimed at the preparation of nano particles of sphere form, and so the second method is employed. 

The term metathesis literally means to transpose. The term double replacement is often used to describe these reactions because the cations switch places with each other. These are chemical reactions that involve an exchange of positive ions between two compounds and that generally take place between two ionic compounds in an aqueous solution. The driving force that causes these reactions to occur is a decrease in the number of ions from the reactants to... 

In Chapter 10, you learned that a chemical reaction can usually be classified as one of five types—synthesis, decomposition, combustion, single-replacement, or double-replacement. In this chapter, you ll investigate a special characteristic of many of these reactions— the ability of elements to gain or lose electrons when they react with other elements. You experimented with this characteristic when you did the DISCOVERY LAB. 

In 1864, ethylene was first expressed graphically in its modem form with a double bond connecting the two carbon atoms (CH2=CH2). This was adopted by Wanklyn to represent the constitutional formula of rosaniline (6), and made public in September of that year at the annual meeting of the British Association for the Advancement of Science, held in Bath. Wanklyn s ethylene-type formula showed two carbon atoms separated from the four hydrogen atoms by a bracket18. The ethylene type, unlike other type formulas, was used only to express the constitutions of coal-tar dyes. Wanklyn argued that the constitutions of the members of the rosaniline series could be expressed by his ethylene type by virtue of known reduction and replacement reactions. Thus he compared the conversion of 6 into colorless leucaniline (10) with the ready reduction of ethylene (ethene) (11) to ethane (12), both of which involved the addition of two hydrogen atoms (Scheme 4)19 21. 

This reaction is one of a type known as a double-replacement or an exchanging-partner reaction. Other types of chemical reactions include the following ... 

The methanol can be replaced by other nucleophilic solvents such as ethanol, acetic acid, or water (in tetrahydrofuran as cosolvent) to give the corresponding ethoxy-, acetoxy-, or hydroxy-esters. Cyclic ethers (substituted tetrahydrofurans and tetrahydropyrans) are formed by intramolecular reaction when the unsaturated ester also contains an appropriately placed hydroxy-group, even in the presence of a reactive solvent. This has been developed into a procedure for the identification, analysis, and isolation of long-chain alcohols and acids having alkene unsaturation in positions 3 (trans only), 4 (cis or tram), or 5 (cis or trans) Such acids (or natural mixtures in which they are present) are reduced to alcohols and subjected to oxymercuration (in DMF as a non-participating solvent) and demercuration. Cyclic ethers are formed only when there is unsaturation at positions 3,4, or 5 other double bonds are unaffected. For example, methyl arachidonatc... 

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