Skeleton equation

Write a skeleton equation in winch the formulas of the reactants appear on the left and those of the products on the right. In this case,... 

The skeleton equation represents a chemical reaction. Which of these are the reactants ... 

The skeleton equation for this chemical reaction violates the law of conservation of mass. Which of these is the correct balanced chemical equation ... 

Suzuki reaction on 4-bromo-6-chloro-3-phenylpyridazine 179 shows that selectivity can also be achieved between a bromine and a chlorine atom and there is no requirement to have an iodine and chlorine atom on the skeleton (Equation 34) <2002SL223>. 

The equations you read and write in the preceding section are skeleton equations, and they re perfectly adequate for a qualitative description of the reaction What are the reactants, and what are the products But if you look closely, you ll see that those equations just don t add up. As written, the mass of 1 mol of each of the reactants doesn t equal the mass of 1 mol of each of the products (see Chapter 7 for details on moles). The skeleton equations brecikthe law of conservation of mass, which states that all the mass present at the beginning of a reaction must be present at the end. To be quantitatively accurate, these equations must be balanced so the masses of reactants and products cire equal. 

Given a skeleton equation (one that includes formulas for reactants and products), count up the uumber of each kind of atom on each side of the equation. 

Reaction of dialkylmagnesium compounds with 2,6-bis(imino)pyridines results in quantitative A-alkylation of the pyridine skeleton (equation 15). 

Write a skeleton equation that includes major reactants and products. For aqueous solution reactions, H20(1), H+(aq), OFF(aq), and spectator ions like Na+(aq) may be ignored at this stage. 

Solution Write the skeleton equation first AgN03 (aq) + Na2S04 (aq) — Ag2S (s) + NaN03 (aq) Use solubility rules to determine the states of the reactants and products. 

Writing skeleton equation with oxidation numbers of chromium and sulphur—... 

This type of equation is often called a skeleton equation. It indicates which reactants were involved and what products were formed, but little else. The addition of a few more symbols can provide much more information. What s missing in the chemical equation that was present in the word equation is the states of the chemicals. The word equation specified sodium metal and hydrogen gas, yet the chemical equation does not indicate this. By rewriting the equation, we can convey this information ... 

Another issue with the skeleton equation above is that the reaction, as written, violates the law of conservation of matter. According to the equation, one sodium atom reacts with one oxygen atom and two hydrogen atoms to produce one sodium atom, one oxygen atom, and three hydrogen atoms. A hydrogen atom has been created, in direct violation of the law of conservation of matter. In reality, this is not how the chemicals react. The reaction really takes place like this ... 

In this first reaction, an acidified solution of potassium dichromate, K2Cr207, reacts with a solution of potassium chloride, KC1. This type of problem periodically appears on the AP test. The skeleton equation for this reaction is ... 

Step 1 Just like the last example, we need to begin by writing the unbalanced skeleton equation in ionic form ... 

Using a chemical formula instead of a chemical name simplifies a chemical equation. It allows you to see at a glance what elements and compounds are involved in the reaction. A skeleton equation lists the chemical formula of each reactant on the left, separated by a + sign if more than one reactant is involved, followed by an arrow — . The chemical formula of each product is listed on the right, again separated by a + sign if more than one product is produced. A skeleton equation also shows the state of each reactant by using the appropriate subscript, as shown in Table 4.1. 

The reaction of sodium metal with chlorine gas to form sodium chloride can be represented by the following skeleton equation ... 

A skeleton equation is more useful to a chemist than a word equation, because it shows the formulas of the compounds involved. It also shows the state of each substance.Try writing some skeleton equations in the following Practice Problems. 

Although skeleton equations are useful, they do not fully describe chemical reactions. To understand why, consider the skeleton equation showing the formation of sodium chloride (above). According to this equation, one sodium atom reacts with one chlorine molecule containing two chlorine atoms. The product is one formula unit of sodium chloride, containing one atom of sodium and one atom of chlorine. Where has the extra chlorine atom gone ... 

A balanced chemical equation reflects the law of conservation of mass. This type of equation shows that there is the same number of each kind of atom on both sides of the equation. Some skeleton equations are, by coincidence, already balanced. For example, examine the reaction of carbon with oxygen to form carbon dioxide, shown in Figure 4.1. In the skeleton equation, one carbon atom and two oxygen atoms are on the left side of the equation, and one carbon atom and two oxygen atoms are on the right side of the equation. 

Most skeleton equations, however, are not balanced, such as the one showing the formation of sodium chloride. Examine Figure 4.2 to see why. There is one sodium atom on each side of the equation, but there are two chlorine atoms on the left side and only one chlorine atom on the right side. 

This skeleton equation is unbalanced. The mass of the reactants is greater than the mass of the product. 

Many skeleton equations are simple enough to balance by a back-and-forth process of reasoning, as you just saw with the sodium chloride reaction. Try balancing the equations in the Practice Problems that follow. 

Copy each skeleton equation into your notebook, and balance it. 

Step 1 Write out the skeleton equation. Ensure that you have copied all the chemical formulas correctly. 

O Write a word equation, skeleton equation, and balanced equation... 

Copy the following skeleton equation for the combustion of pentane, C5H12, into your notebook and balance it. 

Identify the spectator ions in the following skeleton equation. Then write the balanced ionic equation for the reaction. 

Balance each of the following skeleton equations. Classify each chemical reaction. 

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