Aqueous solutions writing chemical equations

Reactions of cations in aqueous solution with sodium hydroxide - Al3+, Fe2+, Fe3+, Cu2+, Ca2+, Zn2, Cr3+,. An excess of sodium hydroxide solution is added slowly to a small volume of the solution containing the cation. This is an exercise in observation, organisational and recording skills and in the ability to write chemical equations - word, molecular and ionic. 

Predict the result of mixing each pair of aqueous solutions. Write a balanced chemical equation if you predict that a precipitate forms. Write NR if you predict that no reaction takes place. 

Let us first look at how we write chemical equations that describe reactions in aqueous solutions. We use three kinds of chemical equations. Table 4-9 shows the kinds of information about each substance that we use in writing equations for reactions in aqueous... 

Protons in aqueous solution are solvated by water molecules, just as other cations are [Figure 4.3(a)]. In writing chemical equations involving protons in water, therefore, we write H aq). 

Write chemical equations for all the acid—base reactions you would predict to occur (based on the pA values you used) when the species you listed above encounter the aqueous sodium bicarbonate solution. (Hint. Consider whether each species might be an acid that could react with NaHCOs.)... 

In writing chemical equations for reactions in aqueous solution, it is often useful to indicate explicitly whelher the dissolved substances are present predominantly as ions or as molecules. Let s reconsider the precipitation reaction between Pb(N03)2 and 2KI, shown previously in Figure 4.4 ... 

PRACTICE EXAMPLE A Write chemical equations for the reactions that occur when NaCN is dissolved in water and when Al(NOg)g is dissolved in water. Then, use data from Appendix D to explain why a precipitate of Al(OH)g forms when equal volumes of 1.0 M aqueous solutions of NaCN and Al(NOg)3 are mixed. 

If Br and 1 occur together in an aqueous solution, 1 can be oxidized to 103 with an excess of Cl2(aq). Simultaneously, Br is oxidized to Br2, which is extracted with CS2(1). Write chemical equations for the reactions that occur. 

Write chemical equations to represent the (a) roasting of galena, PbS (b) reduction of Cu20(s) with charcoal as a reducing agent (c) deposition of pure silver from an aqueous solution of Ag. ... 

P, with the remainder oxygen. The mass spectrum of compound B yields a molar mass of 97.99 g-mol. Write the molecular formula of compound B. (c) Compound B reacts with an aqueous solution of calcium hydroxide to form compound C, a white precipitate. Write balanced chemical equations for the reactions in parts (a), (b), and (c). 

Determine whether an aqueous solution of each of the following salts has a pH equal to, greater than, or less than 7. II pH > 7 or pH < 7, write a chemical equation to justify your answer, (a) K,C204, potassium oxalate (b) Ca(NO )2 ... 

Write the balanced chemical equation for the reaction of chlorine with water in (a) a neutral aqueous solution (b) a dilute basic solution (c) a concentrated basic solution. 

First we write the balanced chemical equation for the reaction. Then we write the equilibrium constant expressions, remembering that gases and solutes in aqueous solution appear in the Kc expression, but pure liquids and pure solids do not. 

Question 4 (Required) 15%—Write the formulas to show the reactants and the products for any five of eight chemical reactions. Each of the reactions occurs in aqueous solution unless otherwise indicated. Represent substances in solution as ions if the substance is extensively ionized. Omit formulas for any ions or molecules that are unchanged by the reaction. In all cases a reaction occurs. You need not balance the equations. 

Answer all three of the following questions. Each question will have two parts—writing the balanced chemical equation and answering a question about the reaction. Coefficients in the balanced chemical equation must be in the lowest whole-number ratio. Do not include formulas for substances that remain unchanged during the reaction. Unless otherwise noted, assume all the reactions occur in aqueous solution. If a substance is extensively ionized and therefore is present as ions in solution, write its formula as ions. 

Write a chemical equation for the reaction between the NaOH and MgS04. Most sulfate compounds exist as ions in aqueous solutions. 

Self-Test 12.1B When acidified potassium permanganate is mixed with a solution of sulfurous acid, H2S03, sulfuric acid and manganese(II) ions are produced. Write the balanced chemical equation for the reaction. In acidic. aqueous solution, H2S03 is present as the nonionized molecules and sulfuric acid is present as HS04" ions. 

Is an acidified aqueous permanganate solution a more powerful oxidizing agent than an acidified aqueous dichromate solution under standard conditions Design an electrochemical cell that could be used to answer the question. Write the chemical equation for the spontaneous reaction between the two reagents and determine the standard cell potential. 

In aqueous solution, the beryllium(II) ion exists as [Be(OH)4]2 ions. Write a chemical equation that illustrates the acidic character of this ion. 

The concentration of nitrate ion in a basic solution can be determined by the following sequence of steps (1) zinc metal reduces nitrate ions to ammonia in a basic aqueous solution (2) the ammonia is passed into a solution containing a known, but excess, amount of HCl(aq) (3) the unreacted HCl(aq) is titrated with a standard NaOH(aq) solution, (a) Write balanced chemical equations for the three reactions. 

Write a chemical equation showing in what respect a Sc3+ ion is a Bronsted acid in aqueous solution. 

One model of an acid-base reaction involves proton transfer from the acid to a solvent water molecule to give an H30+ ion. Write balanced chemical equations that show how aqueous solutions of acidic oxides such as S02 and SO3 can yield H30+ ions. Which of these two oxides gives a higher concentration of H30+ ions Explain. 

One of the substances found in some temporary hard waters is magnesium hydrogencarbonate. Write word and balanced chemical equations to show the effect of heat on this substance in aqueous solution. 

Glycolysis involves 10 biochemical reactions and 16 reactants. Water is not counted as a reactant in writing the stoichiometric number matrix or the conservation matrix for reasons described in Section 6.3. Thus there are six components because C = N — R = 16 — 10 = 6. From a chemical standpoint this is a surprise because the reactants involve only C, H, O, N, and P. Since H and O are not conserved at specified pH in dilute aqueous solution, there are only three conservation equations based on elements. Thus three additional conservation relations arise from the mechanisms of the enzyme-catalyzed reactions in glycolysis. Some of these conservation relations are discussed in Alberty (1992a). At specified pH in dilute aqueous solutions the reactions in glycolysis are... 

Water can act as either an acid or a base, depending on the circumstances. This ability to act as either an acid or a base is referred to by stating that water is amphoteric. Water serves as a base in (17-3) and as an acid in (17-4). Note that the bare H+ (a proton) becomes the hydronium ion, H30+, which is a hydrated proton (H30+ is H+ + H2O) because the bare proton does not really exist in solution. When we write the equilibrium constant expression for an aqueous equilibrium, we can use either the hydrogen ion, H+, or the hydrated form, H30+. Although the proton is hydrated in aqueous solution (as is the hydroxide), the use of H+ and H30+ is up to the style of the person working the problem and the problem itself. More often than not, leaving out water on both sides of the equation is used to keep the solutions to the problems visually simple. So long as water is in its standard state (liquid), it is not included in the K expression and, therefore, not necessary in the chemical equation. 

You need to predict whether or not each pair of aqueous solutions forms an insoluble product (a precipitate). If it does, you need to write a balanced chemical equation. 

A chemical reaction occurs when the following aqueous solutions are mixed sodium sulfide and iron(II) sulfate. Identify the spectator ions. Then write the balanced net ionic equation. 

In different reactions in aqueous solution, the hydrogen carbonate ion can act as an acid or a base. Write the chemical formula of the conjugate acid and the conjugate base of the hydrogen carbonate ion, HC03 (aq). Then complete the following equations. State whether the ion is a Brqnsted-Lowry acid or a base. 

When two solutions are mixed, an insoluble substance sometimes forms that is, a solid forms and separates from the solution. Such a reaction is called a precipitation reaction and the solid that forms is called a precipitate. For example, a precipitation reaction occurs when an aqueous solution of potassium chromate, K2Cr04(aq), which is yellow, is mixed with a colorless aqueous solution containing barium nitrate, Ba(N03)2(aq). As shown in Fig. 4.12, when these solutions are mixed, a yellow solid forms. What is the equation that describes this chemical change To write the equation we must know the identities of the reactants and products. The reactants have already been described K2Cr04(aq) and Ba(N03)2(tf<7). Is there some way we can predict the identities of the products In particular, what is the yellow solid ... 

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