Chemistry Chapter 4

In the following chemical reaction ___(i)____ is oxidized and ____(ii)_____ is reduced. 2Na(s) + Cl2(g) → 2NaCl(s)

Na; Cl2

Common reactions in aqueous solutions

precipitation, neutralization, gas generation, metals: oxidation/reduction

Sodium metal react with water to form sodium hydroxide and hydrogen gas. What is the molecular equation for this reaction?

2Na(s) +2H₂O(l) → 2NaOH (aq) + H₂(g)

What is/are the spectator ion(s) for the reaction that occurs when ammonia (NH₃) reacts with nitric acid (HNO₃) in water?

NO₃⁻

What type of reaction is this: H2SO4 (aq) + 2KOH(aq) → 2H2O(l) + K2SO4(aq)

Neutralization

What type of reaction is this: HClO4(aq) + NaOH(aq) → H2O(l) + NaClO4(aq)

Neutralization

What type of reaction is this: NH3(aq) + HNO3(aq) → NH4NO3(aq)

Neutralization

What type of reaction is this: H2SO4(aq) + Na2S(aq) → H2S(g) + Na2SO4(aq)

Neutralization and gas generation

Strong Electrolyte, Weak electrolyte or nonelectrolyte? glycerol, C3H8O3

non

Strong Electrolyte, Weak electrolyte or nonelectrolyte? glucose, C6H12O6

nonelectrolyte

Solute

other substances dissolved in the solvent

Solubility

refers to how much of a solute can dissolve in a given amount of solvent

Strong Electrolyte, Weak electrolyte or nonelectrolyte? ethanol, CH3CH2OH

non

What oxidation number does K have if it becomes an ion?

+1

What oxidation number does Na have if it becomes an ion?

+1

What oxidation number does H have if it becomes an ion?

+1 or -1

What oxidation number does Ca have if it becomes an ion?

+2

What oxidation number does Mg have if it becomes an ion?

+2

What oxidation number does Al have if it becomes an ion?

+3

What oxidation number does F have if it becomes an ion?

-1

If you dissolve 0.50 moles of LiCl in 0.75 liters of solution, what is the total concentration, in moles/liter, of all of the ions present in solution?

1.3 M ions

What is the mass of chloride ions present in 0.125 L of 0.100 M AlCl3?

1.33 g Cl⁻

You have 250.0 mL of 6.00 M NaOH to which you add 500.0 mL of water. What is the new concentration of NaOH in the diluted solution?

2.00 M

What volume of 0.158 M HCl would be required to neutralize 2.87 g of Mg(OH)₂?

623 mL

When aqueous solutions of BaCl2 and Na2SO4 are mixed together, a precipitate of BaSO4 forms. What is the complete ionic equation for the reaction that occurs?

Ba^2+(aq) + 2Cl^- (aq) + 2Na^+(aq) + SO4^2-(aq) → BaSO4(s) + 2Cl^-(aq) + 2Na^+(aq)

What is the correct net ionic equation for the complete neutralization of phosphoric acid with potassium hydroxide?

H3PO4 (aq) + 3OH^- (aq) → 3H2O(l) + PO4^3-(aq)

Properties of water

High melting and boiling point, expands when freezes (ice floats), dissolves a wide variety of substances, provides an ideal environment in which numerous chemical reactions can occur

Acids

Hydrogen-containing compounds that dissociate in water to produce hydrogen ion and partner anion

What type of reaction is this: BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq)

Precipitation

What type of reaction is this: Pb(NO3)2(aq) + Na2SO4(aq) → PbSO4(s) + 2NaNO3(aq)

Precipitation

Salts of which of the following anions (that is, the combination of the anion with any metal cation) will in general always be soluble in aqueous solutions? Select ALL the correct answers. a. Cl^- NO^3- c. SO4^2- d.CO3^2- e. CH3COO^- (the acetate ion, sometimes also written C2H3O2^-) f. O^2- g. S^2- h. PO4^3-

b. and e.

Salts of which of the following cations (that is, the combination of the cation with any monatomic or polyatomic anion) will in general always be soluble in aqueous solutions? Select ALL the correct answers. a. Ca^2+ b. Na^+ c. Li^+ d. K^+ e. Mg^2+ f. Al^3+ g. NH^4+ h. Hg^+

b., c., d., and g.

What is/are the spectator ion(s) for the following neutralization reaction: 2HCl (aq) + Na₂CO₃(aq) → CO₂(g) + H₂O(l) + 2NaCl(aq) Select ALL of the spectator ions from the list below. a. H+ b. CO3 2- c. Na+ d. Cl e.there are no spectator ions for this reaction

c. and d.

What oxidation number does O have if it becomes an ion?

-2

What oxidation number does S have if it becomes an ion?

-2

What volume of 6.00 M NaOH would be required to prepare 2.00 L of 0.250 M NaOH?

0.0833 L

Dilute solutions of acids are commonly prepared by diluting the concentrated commercial stock solutions of HCl found in chemistry laboratories. The concentration of stock HCl is 12 M. What volume of 12 M HCl should be diluted to 0.50 L with water in order to have a 0.25 M solution of HCl?

10. mL

What mass of PbCl₂ will be produced by precipitation if 100. mL of 1.00 M Pb(NO₃)₂ are mixed with 100. mL of 1.00 M NaCl?

13.9 g

If you dissolve 0.40 moles of AlCl3 in 0.50 liters of solution, what is the total concentration, in moles/liter, of the chloride ions present in solution?

2.4 M

You prepare a solution by placing 325 g of ammonium carbonate in a flask and adding water such that the final volume in the solution is 1.33 liters. What is the concentration of ammonium carbonate in the solution?

2.54 M

You want to make some Kool-Aid. The normal procedure is to add one packet Kool-Aid and one cup of sucrose, C12H22O11, to enough water such that the final volume is 2.000 quarts (1.893 L). Unfortunately you don't have a cup to measure your sucrose, but you do have a balance. You look on line and find the molar concentration of sucrose in Kool-Aid should be 0.309 M. What mass of sucrose is needed to prepare 1.893 liters of Kool-Aid with the proper sugar content?

200. g

Strong Electrolyte, Weak electrolyte or nonelectrolyte? (NH4)2CO3

Strong

Strong Electrolyte, Weak electrolyte or nonelectrolyte? HCl

Strong

Strong Electrolyte, Weak electrolyte or nonelectrolyte? NaOH

Strong

Strong Electrolyte, Weak electrolyte or nonelectrolyte? nitric acid

Strong

Strong Electrolyte, Weak electrolyte or nonelectrolyte? perchloric acid

Strong

Strong Electrolyte, Weak electrolyte or nonelectrolyte? potassium nitrate

Strong

Strong Electrolyte, Weak electrolyte or nonelectrolyte? acetic acid, CH3COOH

Weak

Strong Electrolyte, Weak electrolyte or nonelectrolyte? ammonia, NH3

Weak

Strong Electrolyte, Weak electrolyte or nonelectrolyte? formic acid, HCOOH

Weak

Strong Electrolyte, Weak electrolyte or nonelectrolyte? hypochlorous acid

Weak

Strong Electrolyte, Weak electrolyte or nonelectrolyte? sulfurous acid

Weak

Which of the following metal hydroxides would you expect to be the weakest base? a. NaOH b. Ba(OH)2 c. Ca(OH)2 d. Mg(OH)2 e. this cannot be predicted

d.

What mass of ammonium sulfate is needed to prepare 0.500 liters of a 0.125 M ammonium sulfate solution?

8.26 g

Sodium hydrogen carbonate (NaHCO3) is often used to neutralize spills of acids such as sulfuric acid (H2SO4). The neutralization reaction results in the production of H2O, CO2, and Na2SO4(aq). What mass of NaHCO3 would be required to neutralize 25.0 ml of 6.00M H2SO4?

25.2 g NaHCO₃

Hard water deposits consist primarily of calcium carbonate, an insoluble salt. The addition of acetic acid to a hard water deposit results in the hard water deposit dissolving, and in the process there is bubbling and fizzing consistent with a gas being formed in the reaction. What is the correct net ionic equation for the reaction occurring here?

2CH3COOH(aq) + CaCO3(s) → Ca^2+ + 2CH3COO^- + CO2(g) + H2O(l)

Hard water deposits consist primarily of calcium carbonate, an insoluble salt. The addition of hydrochloric acid to a hard water deposit results in the hard water deposit dissolving, and in the process there is bubbling and fizzing consistent with a gas being formed in the reaction. What is the correct net ionic equation for the reaction occurring here?

2H^+(aq) + CaCO3 (s) → CO2(g) + H2O(l) + Ca^2+(aq)

You go to the doctor and get your blood sugar tested. The lab results show that you have a fasting blood glucose (C6H12O6) level of 75 mg/dL. Convert this blood glucose level to units of millimolar (mM). Note that millimolar means "millimoles/liter", a commonly used unit for expressing the concentrations of solutes in biology and biochemistry.

4.16 mM

What volume of 0.105 M HClO₄ would be required to neutralize 50.0 ml of 0.0875 M NaOH?

41.7 mL

What are the spectator ion(s) for the reaction of the insoluble salt "milk of magnesia", Mg(OH)2, with hydrochloric acid in your stomach.

Cl⁻

Weak electrolytes

Compounds that dissolve in water, but produce only a small concentration of ions when dissolved

Salts

Ionic compounds that are neither acids or bases

Match the following species with the form they exist predominantly as in aqueous solution: HCl

Ions

Match the following species with the form they exist predominantly as in aqueous solution: HNO3

Ions

Match the following species with the form they exist predominantly as in aqueous solution: KNO3

Ions

What is/are the spectator ion(s) for the complete neutralization of phosphoric acid with potassium hydroxide?

K⁺

Write the balanced net ionic equation for the reaction of the insoluble metal hydroxide "milk of magnesia", Mg(OH)2, with hydrochloric acid in your stomach.

Mg(OH)2(s) + 2H^+(aq) → 2 H2O(l) + Mg^2+ (aq)

Match the following species with the form they exist predominantly as in aqueous solution: C3H8O3

Molecules

Match the following species with the form they exist predominantly as in aqueous solution: HF

Molecules

What is the balanced net ionic equation for the reaction of ammonia (NH3) with nitric acid (HNO3) in water?

NH3(aq) + H^+ (aq) → NH^4+ (aq)

Solution

a homogeneous mixture of two or more substances

Write the net ionic equation that will occur when zinc metal is dropped into a solution of hydrochloric acid

Zn(s) + 2H⁺(aq) → Zn²⁺(aq) + H₂(g)

In the following chemical reaction ___(i)____ is oxidized and ____(ii)_____ is reduced. Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

Zn; H+

Bases

compounds that react with hydrogen ions, producing water

Salts of the carbonate ion tend to be insoluble with some exceptions. Which of the following carbonates would you expect to be soluble in aqueous solution? a. (a) MgCO3 b. (b) CaCO3 c. (c) (NH4)2CO3 d. (d) Na2CO3 e. both (c) and (d)

e.

Match the following species with the form they exist predominantly as in aqueous solution: HCOOH (formic acid)

molecules

Match the following species with the form they exist predominantly as in aqueous solution: HNO2

molecules

What type of reaction is this: H2CO3(aq) → CO2(g) + H2O(l)

gas generation

What type of reaction is this: 2CH3COOH(aq) + CaCO3(s) → Ca(CH3COO)2 + CO2(g) + H2O(l)

gas generation and neutralization

What type of reaction is this: 2HCl (aq) + Na2CO3(aq) → CO2(g) + H2O(l) + 2NaCl(aq)

gas generation and neutralization

What type of reaction is this: 2Na(s) + 2H2O(l) → 2NaOH (aq) + H2(g)

gas generation and oxidation/reduction

What type of reaction is this: Cu(s) + 2HCl(aq) → CuCl2(aq) + H2(g)

gas generation and oxidation/reduction

When something is oxidized it ____(i)______ electrons, and when something is reduced it _____(ii)_______ electrons

i- loses; ii- gains

Do strong electrolytes exists predominantly as molecules or ions in an aqueous solution?

ions

Spectator ions

ions in solution that are not involved in a chemical reaction, and appear in identical forms on both sides of the chemical equation

Do nonelectrolytes exists predominantly as molecules or ions in an aqueous solution?

molecules

Do weak electrolytes exists predominantly as molecules or ions in an aqueous solution?

molecules

Match the following species with the form they exist predominantly as in aqueous solution: CH3COOH (acetic acid)

molecules

Strong electrolytes

salts, acids, and bases that dissolve completely or nearly completely in water to form ions

Strong Electrolyte, Weak electrolyte or nonelectrolyte? sulfuric acid

strong

Solution concentration

the amount of solute dissolved in a given quantity of solvent or solution

Solvent

the substance in the solution present in the greatest quantity

Hard water deposits consist primarily of calcium carbonate, an insoluble salt. The addition of acetic acid to a hard water deposit results in the hard water deposit dissolving, and in the process there is bubbling and fizzing consistent with a gas being formed in the reaction. What is/are the spectator ion(s) for this reaction?

there are no spectator ions for this reaction

Sodium metal react with water to form sodium hydroxide and hydrogen gas. What is/are the spectator ion(s) for this reaction?

there are no spectator ions for this reaction

Aqueous solution

water is the solvent

Strong Electrolyte, Weak electrolyte or nonelectrolyte? nitrous acid

weak