Chapter 4

Define: (a) solvent, (b) solute, (c) concentration.

Describe: (a) concentrated, (b) dilute, (c) saturated, (d) unsaturated, (e) supersaturated, (f) solubility.

Describe what will happen if a crystal of sugar is added to (a) a saturated sugar solution, (b) a supersaturated solution of sugar, and (c) an unsaturated solution of sugar.

What is the meaning of the term precipitate? What condition must exist for a precipitate to form spontaneously in a solution?

Why is an electrolyte able to conduct electricity while a nonelectrolyte cannot?

Which compounds are likely to be electrolytes and which are likely to be nonelectrolytes? \(\mathrm{CuBr}_{2}\), \(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\), \(\mathrm{CH}_{3} \mathrm{OH},\) iron(II) chloride, \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}\), ethanol

What does it mean when we say that an ion is "hydrated?"

Define "dissociation" as it applies to ionic compounds that dissolve in water. Why don't strong bases "ionize"?

How can you tell that the following is a net ionic equation? $$ \mathrm{Al}^{3+}(a q)+3 \mathrm{OH}^{-}(a q) \longrightarrow \mathrm{Al}(\mathrm{OH})_{3}(s) $$

Give two general properties of an acid. Give two general properties of a base.

How did Arrhenius define an acid and a base?

How does ionization differ from dissociation?

Which of the following oxides would yield an acidic solution when they react with water? Which would give a basic solution? (a) \(\mathrm{P}_{4} \mathrm{O}_{10},\) (b) \(\mathrm{K}_{2} \mathrm{O},\) (c) \(\mathrm{SeO}_{3},\) (d) \(\mathrm{Cl}_{2} \mathrm{O}_{7}\)

What is a dynamic equilibrium? Using acetic acid as an example, describe why all the \(\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\) molecules are not ionized in water.

Why don't we use double arrows in the equation for the reaction of a strong acid with water?

Which of the following are strong acids? (a) \(\mathrm{HCN},\) (b) \(\mathrm{HNO}_{3}\), (c) \(\mathrm{H}_{2} \mathrm{SO}_{3},\) (d) HCl, (e) \(\mathrm{HCHO}_{2}\), (f) \(\mathrm{HNO}_{2}\)

Which are classified as strong bases when dissolved in water? (a) \(\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{~N},\) (b) \(\mathrm{Ba}(\mathrm{OH})_{2}\), (c) KOH, (d) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}\) (e) \(\mathrm{Cs}_{2} \mathrm{O}\) (f) \(\mathrm{N}_{2} \mathrm{O}_{5}\)

Explain the difference between the names of \(\mathrm{H}_{2} \mathrm{Se}(g)\) and \(\mathrm{H}_{2} \mathrm{Se}(a q)\)

Explain how the two acid salts of phosphoric acids are formed from the reaction of \(\mathrm{H}_{3} \mathrm{PO}_{4}\) with \(\mathrm{NaOH},\) and name them.

Silver bromide is "insoluble." What does this mean about the concentrations of \(\mathrm{Ag}^{+}\) and \(\mathrm{Br}^{-}\) in a saturated solution of AgBr? What makes it possible for a precipitate of \(\mathrm{AgBr}\) to form when solutions of the soluble salts \(\mathrm{AgNO}_{3}\) and \(\mathrm{NaBr}\) are mixed?

What is the definition of molarity? Show that the ratio of millimoles (mmol) to milliliters (mL) is equivalent to the ratio of moles to liters.

A solution is labeled \(0.25 M\) HCl. Construct two conversion factors that relate moles of \(\mathrm{HCl}\) to the volume of solution expressed in liters.

When the units molarity and liter are multiplied, what are the resulting units?

When a solution labeled \(0.50 \mathrm{M} \mathrm{HNO}_{3}\) is diluted with water to give \(0.25 \mathrm{M} \mathrm{HNO}_{3}\), what happens to the number of moles of \(\mathrm{HNO}_{3}\) in the solution?

Describe the steps to take in diluting a solution of \(0.500 \mathrm{M}\) \(\mathrm{HCl}\) to make \(250 \mathrm{~mL}\) of \(0.100 \mathrm{M} \mathrm{HCl}\)

What is the difference between a qualitative analysis and quantitative analysis?

Describe each of the following: (a) buret, (b) titration, (c) titrant, and (d) end point.

What is the function of an indicator in a titration? What color is phenolphthalein in (a) an acidic solution and (b) a basic solution?

Classify each of the following as a strong electrolyte or nonelectrolyte. (a) \(\mathrm{KCl}\) (b) \(\mathrm{C}_{3} \mathrm{H}_{5}(\mathrm{OH})_{3} \quad\) (glycerin) (c) \(\mathrm{NaOH}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \quad\) (ethanol)

Write balanced ionic and net ionic equations for these reactions. (a) \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}(a q)+\mathrm{BaCl}_{2}(a q) \longrightarrow\) $$ \mathrm{NH}_{4} \mathrm{Cl}(a q)+\mathrm{BaCO}_{3}(s) $$ (b) \(\mathrm{CuCl}_{2}(a q)+\mathrm{NaOH}(a q) \longrightarrow\) $$ \mathrm{Cu}(\mathrm{OH})_{2}(s)+\mathrm{NaCl}(a q) $$ (c) \(\mathrm{FeSO}_{4}(a q)+\mathrm{Na}_{3} \mathrm{PO}_{4}(a q) \longrightarrow\) \(\mathrm{Fe}_{3}\left(\mathrm{PO}_{4}\right)_{2}(s)+\mathrm{Na}_{2} \mathrm{SO}_{4}(a q)\) (d) \(\mathrm{AgC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}(a q)+\mathrm{NiCl}_{2}(a q) \longrightarrow\) \(\mathrm{AgCl}(s)+\mathrm{Ni}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}(a q)\)

Microscopic imperfections in glass are usually harmless, but imperfections of nickel(II) sulfide can cause the glass to crack spontaneously. To study this process, nickel(II) sulfide can be synthesized from sodium sulfide and nickel(II) sulfate. $$ \begin{array}{r} \mathrm{Ni}^{2+}(a q)+\mathrm{SO}_{4}^{2-}(a q)+2 \mathrm{Na}^{+}(a q)+\mathrm{S}^{2-}(a q) \longrightarrow \\ \mathrm{NiS}(s)+2 \mathrm{Na}^{+}(a q)+\mathrm{SO}_{4}^{2-}(a q) \end{array} $$ Which are the spectator ions? Write the net ionic equation.

Write an equation for the ionization of hydrogen bromide, a molecular substance and a strong acid, in water.

When chloric acid reacts with water, it reacts as a strong acid. Write an equation for this reaction.

Hydrazine is a toxic substance that can form when household ammonia is mixed with a bleach such as Clorox. Its formula is \(\mathrm{N}_{2} \mathrm{H}_{4}\), and it is a weak base. Write a chemical equation showing its reaction with water.

Pyridine, \(\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{~N},\) is a fishy-smelling compound used as an intermediate in making insecticides. It is a weak base. Write a chemical equation showing its reaction with water.

Pentanoic acid, \(\mathrm{HC}_{5} \mathrm{H}_{9} \mathrm{O}_{2}\), is found in a plant called valerian, which cats seem to like almost as much as catnip, and is a weak acid. Write an equation showing its reaction with water

Atmospheric carbon dioxide dissolves in raindrops, resulting in a solution of carbonic acid that makes rain slightly acidic. Since carbonic acid is a diprotic acid, write the chemical equations that describe its stepwise ionization.

Name these acids: (a) \(\mathrm{HF}(g),\) (b) \(\mathrm{HF}(a q)\)

Name these acids that bromine forms. (a) \(\mathrm{HBrO}_{4}\), (b) \(\mathrm{HBrO}_{3}\), (c) \(\mathrm{HBrO}_{2},\) (d) \(\mathrm{HBrO}\) (e) \(\mathrm{HBr}\)

Write the formula for (a) chromic acid, (b) carbonic acid, and (c) oxalic acid.

Write the formula for (a) permanganic acid, (b) sulfurous acid, and (c) dichromic acid.

Name the following acid salts: (a) \(\mathrm{NaHCO}_{3}\), (b) \(\mathrm{KH}_{2} \mathrm{PO}_{4}\) (c) \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{HPO}_{4}\)

Name the following acid salts: (a) \(\mathrm{KHSO}_{4},\) (b) \(\mathrm{LiHSO}_{3}\), (c) \(\mathrm{PbHAsO}_{4}\)

The formula for the sulfite ion is \(\mathrm{SO}_{3}^{2-}\). What is the formula for sulfuric acid?

Butanoic acid (also called butyric acid), \(\mathrm{HC}_{4} \mathrm{H}_{7} \mathrm{O}_{2},\) gives rancid butter its bad odor. What is the name of the salt \(\mathrm{NaC}_{4} \mathrm{H}_{7} \mathrm{O}_{2} ?\)

Oxalic acid, \(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4},\) is the poison in rhubarb leaves. Name its potassium salt.

Sodium formate, \(\mathrm{NaCHO}_{2},\) is used in fabric dyeing. The acid form is found in the venom of ant bites. What is the name of the acid that this salt can be made from?

Potassium stearate, \(\mathrm{KC}_{18} \mathrm{H}_{36} \mathrm{O}_{2},\) is an effective soap for washing your hands or clothes. What acid is reacted with \(\mathrm{KOH}\) to make this compound?

Predict which compounds are soluble in water. (a) \(\mathrm{HgBr}_{2}\) (b) \(\mathrm{Sr}\left(\mathrm{NO}_{3}\right)_{2}\) (c) \(\mathrm{Hg}_{2} \mathrm{Br}_{2}\) (d) ammonium phosphate (e) lead(II) iodide (f) lead(II) acetate

Complete and balance the following molecular equations, being careful to apply the solubility rules. Write balanced ionic and net ionic equations for the reactions. (a) \(\mathrm{FeSO}_{4}(a q)+\mathrm{K}_{3} \mathrm{PO}_{4}(a q) \longrightarrow\) (b) \(\mathrm{AgC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}(a q)+\mathrm{AlCl}_{3}(a q) \longrightarrow\) (c) chromium(III) chloride \(+\) barium hydroxide