Balancing equations charges

Governing equation Boundary conditions Surface charge balance equation Charge on particle surface EDL potential... 

The second type of equation is a charge balance equation. A charge balance equation is a statement of solution electroneutrality. 

Note that the concentration of Ca + is multiplied by 2, and that the concentrations of H3O+ and OH are also included. Charge balance equations must be written carefully since every ion in solution must be included. This presents a problem when the concentration of one ion in solution is held constant by a reagent of unspecified composition. For example, in many situations pH is held constant using a buffer. If the composition of the buffer is not specified, then a charge balance equation cannot be written. 

Write a mass balance and charge balance equations for a 0.10 M solution of NaHC03. 

Substituting these equations, along with the equation for into the charge balance equation gives us... 

Substituting equation 6.46 into the charge balance equation and solving for [A ] gives... 

You should be able to describe a system at equilibrium both qualitatively and quantitatively. Rigorous solutions to equilibrium problems can be developed by combining equilibrium constant expressions with appropriate mass balance and charge balance equations. Using this systematic approach, you can solve some quite complicated equilibrium problems. When a less rigorous an-... 

Write charge balance and mass balance equations for the following solutions... 

To balance equations 10.2 and 10.3 in terms of electrical charge it has been necessary to add four electrons to the right-hand side of equation 10.2 and to the left-hand-side of equation 10.3. However, simple addition and rationalisation of equations 10.2 and 10.3 yields equation 10.1. 

In a balanced equation for a chemical reaction, charge is conserved. 

Balance the equations for the reactions given below. For each balanced equation, sum up the charges of the reactants and compare to the sum of the charges of the products. 

Because electrons can be neither lost nor created in a chemical reaction, all the electrons lost by the species being oxidized must be transferred to the species being reduced. Because electrons are charged, the total charge of the reactants must be the same as the total charge of the products. Therefore, when balancing the chemical equation for a redox reaction, we have to balance the charges as well as the atoms. 

At first glance, the equation appears to be balanced, because it has the same number of each kind of atom on each side. Flowever, each copper atom has lost two electrons, whereas each silver atom has gained only one. To balance the electrons, we have to balance the charge. Therefore, we need to write... 

If an ion is doubly charged, wc multiply its concentration by 2 in the charge balance equation, and likewise for triply charged ions. 

In very dilute solutions of strong acids and bases, the pH is significantly affected by the autoprotolysis of water. The pH is determined by solving three simultaneous equations the charge-balance equation, the material-balance equation, and the expression for Kw. 

Students at senior high school/college level are expected to be able to undertake this type of manipulation of symbols to produce balanced equations from half equations (whilst also adding the electrode potentials to check if the reaction is feasible). The resultant equation balances in terms of both the quantity of each element represented (2Mn, 80, 16H, lOBr) and in terms of overall charge (—2 - -16 — 10 = - -4). 

In a batch vessel, the question of good mixing will arise at the start of the batch and whenever an ingredient is added to the batch. The component balance, Equation (1.21), assumes that uniform mixing is achieved before any appreciable reaction occurs. This will be true if Equation (1.55) is satisfied. Consider the same vessel being used as a flow reactor. Now, the mixing time must be short compared with the mean residence time, else newly charged... 

Each side of this balanced equation has a net charge of +2. Remember, however, that the net ionic equation does not show all of the species present in solution, in this example. Cl ions balance out the positive charges of ond H3 O. All solutions... 

To summarize, the equation for a nuclear reaction is balanced when the total charge and total mass number of the products equals the total charge and total mass number of the reactants. This conservation requirement is one reason why the symbol for any nuclide includes its charge number (Z) as a subscript and its mass number as a superscript. These features provide a convenient way to keep track of charge and mass balances. Notice that in the equation for neutron decay, the sum of the subscripts for reactants equals the sum of the subscripts for products. Likewise, the sum of the superscripts for reactants equals the sum of the superscripts for products. We demonstrate how to balance equations for other reactions as they are introduced. 

In electrolyte solutions, nonideality of the system is much more pronounced than in solutions with uncharged species. This can be seen in particular from the fact that electrolyte solutions start to depart from an ideal state at lower concentrations. Hence, activities are always used in the thermodynamic equations for these solutions. It is in isolated instances only, when these equations are combined with other equations involving the number of ions per unit volume (e.g., equations for the balance of charges), that concentrations must be used and some error thus is introduced. 

A chemical equation describes a chemical reaction in many ways as an empirical formula describes a chemical compound. The equation describes not only which substances react, but the relative number of moles of each undergoing reaction and the relative number of moles of each product formed. Note especially that it is the mole ratios in which the substances react, not how much is present, that the equation describes. In order to show the quantitative relationships, the equation must be balanced. That is, it must have the same number of atoms of each element used up and produced (except for special equations that describe nuclear reactions). The law of conservation of mass is thus obeyed, and also the "law of conservation of atoms. Coefficients are used before the formulas for elements and compounds to tell how many formula units of that substance are involved in the reaction. A coefficient does not imply any chemical bonding between units of the substance it is placed before. The number of atoms involved in each formula unit is multiplied by the coefficient to get the total number of atoms of each element involved. Later, when equations with individual ions are written (Chap. 9), the net charge on each side of the equation, as well as the numbers of atoms of each element, must be the same to have a balanced equation. The absence of a coefficient in a balanced equation implies a coefficient of 1. 

According to the mass balance Equation 3.28, the expression in parentheses is Mi. Further, the charge Z, on a species component is the same as the charge z, on the corresponding basis species, since components and species share the same stoichiometry. Substituting, the electroneutrality condition becomes,... 

The two half-equations then are balanced for charge using electrons and combined to produce the net ionic equation. Finally, nitrate spectator ions are added to give the balanced equation. 

Step 4 Balance the charges on both sides of the equation by adding the appropriate number of electrons (e ) to whichever side is deficient in negative charges. The charge balancing is accomplished as if the electron is like any chemical species—place the appropriate multiplying coefficient in front of eh... 

Step 5 Multiply through both equations by appropriate coefficients, so that the number of electrons involved in both half-reactions is the same. This has the effect of making the total charge loss equal to the total charge gain and thus eliminates electrons from the final balanced equation, as you will see in step 6. 

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