chapter 4 textbook questions

To what volume should you dilute 50.0 mL of a 12 M stock HNO3 solution to obtain a 0.100 M HNO3 solution?

6.0 L

Mercury(I) ions (Hg2 2+) can be removed from solution by precipitation with Cl- . Suppose that a solution contains aqueous Hg2(NO3)2. Write complete ionic and net ionic equations to show the reaction of aqueous Hg2(NO3)2 with aqueous sodium chloride to form solid Hg2Cl2 and aqueous sodium nitrate.

Complete: Hg2 2+(aq)+2NO3 -(aq)+2Na+(aq)+2Cl-(aq)->Hg2Cl2(s)+2Na+(aq)+2NO3 -(aq) Net: Hg2 2+(aq) + 2 Cl-(aq)hHg2Cl2(s)

Write a molecular and a net ionic equation for the reaction that occurs between aqueous H2SO4 and aqueous LiOH

H2SO4(aq) + 2 LiOH(aq)--> 2 H2O(l) + Li2SO4(aq) H+(aq) + OH-(aq)hH2O(aq)

What is the oxidation state of carbon in CO3 2- ? a) +4 b) +3 c) -3 d) -2

a

How many moles of KCl are contained in each solution? a. 0.556 L of a 2.3 M KCl solution b. 1.8 L of a 0.85 M KCl solution c. 114 mL of a 1.85 M KCl solution

a. 1.3 mol b. 1.5 mol c. 0.211 mol

Assign an oxidation state to each atom in each element, ion, or compound. (a) Cr (b) Cr 3+ (c) CCl 4 (d) SrBr 2 (e) SO 3 (f) NO3-

a. Cr = 0 b. Cr3+ = +3 c. Cl- = -1, C = +4 d. Br = -1, Sr = +2 e. O = -2, S = +6 f. O = -2, N = +5

Write a molecular equation for the precipitation reaction that occurs (if any) when each pair of aqueous solutions is mixed. If no reaction occurs, write "NO REACTION." a. potassium carbonate and lead(II) nitrate b. lithium sulfate and lead(II) acetate c. copper(II) nitrate and magnesium sulfide d. strontium nitrate and potassium iodide

a. K2CO3(aq) + Pb(NO3)2(aq)->PbCO3(s) + 2 KNO3(aq) b. Li2SO4(aq) + Pb(C2H3O2)2(aq)-> PbSO4(s) + 2 LiC2H3O2(aq) c. Cu(NO3)2(aq) + MgS(aq)-> CuS(s) + Mg(NO3)2(aq) d. NO REACTION

Complete and balance each equation. If no reaction occurs, write "NO REACTION." a. LiI(aq) + BaS(aq) S b. KCl(aq) + CaS(aq) S c. CrBr2(aq) + Na2CO3(aq) S d. NaOH(aq) + FeCl3(aq) S

a. NO REACTION b. NO REACTION c. CrBr2(aq)+Na2CO3(aq)->CrCO3(s) + 2 NaBr(aq) d. 3 NaOH(aq) + FeCl3(aq)->Fe(OH)3(s) + 3 NaCl(aq)

For the following reaction, determine the limiting reactant for each of the initial amounts of reactants. 2 Na(s) + Br2(g) --> 2 NaBr(s) a. 2 mol Na, 2 mol Br2 b. 1.8 mol Na, 1.4 mol Br2 c. 2.5 mol Na, 1 mol Br2 d. 12.6 mol Na, 6.9 mol Br2

a. Na b. Na c. Br2 d. Na

Complete and balance each combustion reaction equation. a. S(s) + O2(g) -> b. C3H6(g) + O2(g) -> c. Ca(s) + O2(g) -> d. C5H12S(l) + O2(g) ->

a. S(s) + O2(g)->SO2(g) b. 2 C3H6(g) + 9 O2(g)->6 CO2(g) + 6 H2O(g) c. 2 Ca(s) + O2(g)->2 CaO(g) d. C5H12S(l) + 9 O2(g)-> 5 CO2(g) + SO2(g) + 6 H2O(g)

What volume of a 6.00 M NaNO3 solution should you use to make 0.525 L of a 1.20 M NaNO3 solution?

0.105 L

Write an equation for the precipitation reaction that occurs (if any) when solutions of ammonium chloride and iron(III) nitrate are mixed.

NH4Cl(aq) + Fe(NO3)3(aq) --> NO REACTION

What is the net ionic equation for the reaction that occurs when aqueous solutions of KOH and SrCl2 are mixed? a) K+(aq) + Cl-(aq) S KCl(s) b) Sr2+ (aq) + 2 OH-(aq) S Sr(OH)2(s) c) H+(aq) + OH-(aq) S H2O(l) d) None of the above because no reaction occurs

cb

A reaction has a theoretical yield of 45.8 g. When the reaction is carried out, 37.2 g of the product is obtained. What is the percent yield? a) 55.1% b) 44.8% c) 123% d) 81.2%

d

Calculate the molarity of a solution made by adding 45.4 g of NaNO3 to a flask and dissolving it with water to create a total volume of 2.50 L.

0.214 M NaNO3

If 123 mL of a 1.1 M glucose solution is diluted to 500.0 mL, what is the molarity of the diluted solution?

0.27 M

Zinc(II) sulfide reacts with oxygen according to the reaction: 2 ZnS(s) + 3 O2(g) -> 2 ZnO(s) + 2 SO2(g) A reaction mixture initially contains 4.2 mol ZnS and 6.8 mol O2. Once the reaction has occurred as completely as possible, what amount (in moles) of the excess reactant is left?

0.5 mol O2

To what volume should you dilute 0.200 L of a 15.0 M NaOH solution to obtain a 3.00 M NaOH solution?

1.00 L

Write a molecular equation for the gas-evolution reaction that occurs when you mix aqueous nitric acid and aqueous sodium carbonate.

2 HNO3 (aq) + Na2CO3 (aq)-->H2O(l) + CO2(g) + 2 NaNO3 (aq)

Write an equation for the precipitation reaction that occurs (if any) when solutions of sodium hydroxide and copper(II) bromide are mixed.

2 NaOH(aq) + CuBr2(aq) --> Cu(OH)2(s) + 2 NaBr(aq)

Hard water often contains dissolved Ca2+ and Mg2+ ions. One way to soften water is to add phosphates. The phosphate ion forms insoluble precipitates with calcium and magnesium ions, removing them from solution. A solution is 0.050 M in calcium chloride and 0.085 M in magnesium nitrate. What mass of sodium phosphate would have to be added to 1.5 L of this solution to completely eliminate the hard water ions? Assume complete reaction.

22 g

How many mL of a 0.155 M KCl solution contain 2.55 g KCl?

221 mL of KCl solution

What volume (in mL) of 0.200 M NaOH do we need to titrate 35.00 mL of 0.140 M HBr to the equivalence point?

24.5 mL NaOH solution

In photosynthesis, plants convert carbon dioxide and water into glucose (C6 H12 O6) according to the reaction: 6 CO2 (g) + 6 H2 O (l) sunlight 6 O2 (g) + C6 H12 O6 (aq) Suppose you determine that a particular plant consumes 37.8 g of CO2 in one week. Assuming that there is more than enough water present to react with all of the CO 2 , what mass of glucose (in grams) can the plant synthesize from the CO 2 ?

25.8 g C6 H12 O6

Magnesium hydroxide, the active ingredient in milk of magnesia, neutralizes stomach acid, primarily HCl, according to the reaction: Mg(OH)2(aq) + 2 HCl(aq) S2 H2O(l) + MgCl2(aq) What mass of HCl, in grams, is neutralized by a dose of milk of magnesia containing 3.26 g Mg(OH)2?

4.08 g HCl

Use oxidation states to identify the element that is oxidized and the element that is reduced in the following redox reaction. Sn(s) + 4 HNO3 (aq)-->SnO2 (s) + 4 NO2 (g) + 2 H2O(g)

Sn is oxidized and N is reduced

A solution contains Ag+ and Hg2+ ions. The addition of 0.100 L of 1.22 M NaI solution is just enough to precipitate all the ions as AgI and HgI2. The total mass of the precipitate is 28.1 g. Find the mass of AgI in the precipitate

11.8 g AgI

A particular kind of emergency breathing apparatus—often placed in mines, caves, or other places where oxygen might become depleted or where the air might become poisoned— works via the following chemical reaction: 4 KO2 (s) + 2 CO2 (g) -> 2 K2CO3 (s) + 3 O2(g) Notice that the reaction produces O2 , which can be breathed, and absorbs CO2, a product of respiration. Suppose you work for a company interested in producing a self-rescue breathing apparatus (based on the given reaction) that would allow the user to survive for 10 minutes in an emergency situation. What are the important chemical considerations in designing such a unit? Estimate how much KO2 would be required for the apparatus. (Find any necessary additional information—such as human breathing rates—from appropriate sources. Assume that normal air is 20% oxygen.)

14 g KO2 . In designing the unit you would need to consider the theoretical yield and % yield of the reaction, how changing the limiting reactant would affect the reaction, and the stoichiometry between KO2 and O2 to determine the mass of KO2 required to produce enough O2 for 10 minutes. You might also consider the speed of the reaction and whether or not the reaction produced heat. Additionally, because your body does not use 100% of the oxygen taken in with each breath, the apparatus would only need to replenish the oxygen used. The percentage of oxygen in air is about 20% and the percentage in exhaled air is about 16%, so we will assume that 4% of the air would need to be replenished with oxygen.

Write a balanced equation for the complete combustion of liquid C2H5SH

2 C2H5SH(l) + 9 O2(g)-> 4 CO2(g) + 2 SO2(g) + 6 H2O(g)

Consider the unbalanced equation for the combustion of hexane: C6H14(g) + O2(g) --> CO2(g) + H2O(g) Balance the equation and determine how many moles of O2 are required to react completely with 7.2 moles of C6H14.

2 C6H14(g) + 19 O2(g)--> 12 CO2(g) + 14 H2O(g), 68 mol O2

Write a balanced equation for the combustion of liquid methyl alcohol (CH 3 OH).

2 CH3OH(l) + 3 O2 (g)-> 2 CO2(g) + 4 H2O(g)

Consider the following reaction occurring in aqueous solution: 2 HI(aq) + Ba(OH)2(aq)->2 H2O(l) + BaI2(aq) Write the complete ionic equation and net ionic equation for this reaction.

2 H +(aq) + 2 I -(aq) + Ba2+(aq) + 2 OH -(aq)-->2 H2O(l) + Ba2+(aq) + 2 I -(aq) H+(aq) + OH-(aq)-->H2O(l)

Write a molecular and net ionic equation for the reaction between aqueous HI and aqueous Ba(OH) 2 .

2 H+(aq) + 2 OH-(aq) -->2 H2O(l) or simply H+(aq) + OH-(aq) -->H2O(l)

Write a net ionic equation for the reaction that occurs when you mix hydroiodic acid with calcium sulfide

2 H+(aq) + S2-(aq)-->H2S(g)

Write a molecular equation for the gas-evolution reaction that occurs when you mix aqueous hydrobromic acid and aqueous potassium sulfite.

2 HBr(aq) + K2SO3(aq)--> H2O(l) + SO2(g) + 2 KBr(aq)

If you dissolve 25.5 g KBr in enough water to make 1.75 L of solution, what is the molarity of the solution?

0.122 M

The titration of a 10.00 mL sample of an HCl solution of unknown concentration requires 12.54 mL of a 0.100 M NaOH solution to reach the equivalence point. What is the concentration of the unknown HCl solution in M?

0.125 M HCl

Predict whether each compound is soluble or insoluble. (a) PbCl2 (b) CuCl2 (c) Ca(NO3)2 (d) BaSO4

(a) Insoluble. Compounds containing Cl- are normally soluble, but Pb2+ is an exception. (b) Soluble. Compounds containing Cl- are normally soluble and Cu2+ is not an exception. (c) Soluble. Compounds containing NO3 - are always soluble. (d) Insoluble. Compounds containing SO4 2- are normally soluble, but Ba2+ is an exception.

A 25.00 mL sample of an unknown HClO4 solution requires titration with 22.62 mL of 0.2000 M NaOH to reach the equivalence point. What is the concentration of the unknown HClO4 solution? The neutralization reaction is HClO4(aq) + NaOH(aq) -> H2O(l) + NaClO4(aq)

0.1810 M HClO4

The reaction of NH3 and O2 forms NO and water. The NO can be used to convert P4 to P4O6, forming N2 in the process. The P4O6 can be treated with water to form H3PO3, which forms PH3 and H3PO4 when heated. Find the mass of PH3 that forms from the reaction of 1.00 g NH3.

0.333 g PH3

What volume (in L) of 0.150 M KCl solution will completely react with 0.150 L of a 0.175 M Pb(NO3)2 solution according to the following balanced chemical equation? 2 KCl(aq) + Pb(NO3)2(aq)SPbCl2(s) + 2 KNO3(aq)

0.350 L KCl solution

People often use sodium bicarbonate as an antacid to neutralize excess hydrochloric acid in an upset stomach. What mass of hydrochloric acid (in grams) can 2.5 g of sodium bicarbonate neutralize? (Hint: Begin by writing a balanced equation for the reaction between aqueous sodium bicarbonate and aqueous hydrochloric acid.)

1.1 g

A mixture of C3H8 and C2H2 has a mass of 2.0 g. It is burned in excess O2 to form a mixture of water and carbon dioxide that contains 1.5 times as many moles of CO2 as of water. Find the mass of C2H2 in the original mixture.

1.6 g C2H2

How many liters of a 0.125 M NaOH solution contain 0.255 mol of NaOH?

2.04 L solution

What is the minimum amount of 6.0 M H2SO4 necessary to produce 25.0 g of H2 (g) according to the reaction between aluminum and sulfuric acid? 2 Al(s) + 3 H2SO4(aq) -> Al2(SO4)3(aq) + 3 H2(g)

2.1 L

Iron(III) sulfide reacts with carbon monoxide according to the equation: Fe2O3(s) + 3 CO(g) --> 2 Fe(s) + 3 CO2(g) A reaction mixture initially contains 22.55 g Fe2O3 and 14.78 g CO. Once the reaction has occurred as completely as possible, what mass (in g) of the excess reactant is left?

2.91 grams CO2 remaining

Another component of acid rain is nitric acid, which forms when NO2 , also a pollutant, reacts with oxygen and water according to the simplified equation: 4 NO2 (g) + O2 (g) + 2 H2O (l)S 4 HNO3 (aq) The generation of the electricity used by a medium-sized home produces about 16 kg of NO2 per year. Assuming that there is adequate O2 and H2O , what mass of HNO3 , in kg, can form from this amount of NO2 pollutant?

22 kg HNO3

The combustion of gasoline produces carbon dioxide and water. Assume gasoline to be pure octane ( C8H18 ) and calculate the mass (in kg) of carbon dioxide that is added to the atmosphere per 1.0 kg of octane burned. (Hint: Begin by writing a balanced equation for the combustion reaction.)

3.1 kg

The density of a 20.0% by mass ethylene glycol ( C2H6O2 ) solution in water is 1.03 g/mL. Find the molarity of the solution.

3.32 M

A liquid fuel mixture contains 30.35% hexane ( C6H14 ), 15.85% heptane ( C7H16 ), and the rest octane ( C8H18 ). What maximum mass of carbon dioxide is produced by the complete combustion of 10.0 kg of this fuel mixture?

30.8 kg CO2

A laboratory procedure calls for making 400.0 mL of a 1.1 M NaNO3 solution. What mass of NaNO3 (in g) is needed?

37 g

Consider the precipitation reaction: 2 Na3PO4(aq) + 3 CuCl2(aq) -> Cu3(PO4)2(s) + 6 NaCl(aq) What volume of 0.175 M Na3PO4 solution is necessary to completely react with 95.4 mL of 0.102 M CuCl2 ?

37.1 mL

Hydrolysis of the compound B5H9 forms boric acid, H3BO3. Fusion of boric acid with sodium oxide forms a borate salt, Na2B4O7. Without writing complete equations, find the mass (in grams) of B5H9 required to form 151 g of the borate salt by this reaction sequence.

37.9 g B5H9

Sulfuric acid (H2 SO4) is a component of acid rain that forms when SO2 , a pollutant, reacts with oxygen and water according to the simplified reaction: 2 SO2 (g) + O2 (g) + 2 H2O (l)-->2 H2SO4 (aq) The generation of the electricity used by a medium-sized home produces about 25 kg of SO2 per year. Assuming that there is more than enough O2 and H2O , what mass of H2SO4 , in kg, can form from this much SO2 ?

38 kg H2SO4

How many grams of sucrose (C12H22O11) are in 1.55 L of 0.758 M sucrose solution?

402 g C12H22O11

What mass of KBr (in grams) do you need to make 250.0 mL of a 1.50 M KBr solution?

44.6 g KBr

Recall from Section 4.6 that sodium carbonate is often added to laundry detergents to soften hard water and make the detergent more effective. Suppose that a particular detergent mixture is designed to soften hard water that is 3.5 * 10-3 M in Ca2+ and 1.1 * 10-3 M in Mg2+ and that the average capacity of a washing machine is 19.5 gallons of water. If the detergent requires using 0.65 kg detergent per load of laundry, what percentage (by mass) of the detergent should be sodium carbonate in order to completely precipitate all of the calcium and magnesium ions in an average load of laundry water?

5.5% by mass

What volume (in mL) of a 0.150 M HNO3 solution will completely react with 35.7 mL of a 0.108 M Na2CO3 solution according to the following balanced chemical equation? Na2CO3(aq) + 2 HNO3(aq) S2 NaNO3(aq) + CO2(g) + H2O(l) what mass (in grams) of carbon dioxide forms?

51.4 mL HNO3 solution 0.170 g CO2

Find the mass of barium metal (in grams) that must react with O2 to produce enough barium oxide to prepare 1.0 L of a 0.10 M solution of OH-.

6.9 g

To what volume (in mL) should you dilute 100.0 mL of a 5.00 M CaCl2 solution to obtain a 0.750 M CaCl2 solution?

667 mL

The titration of a 20.0 mL sample of an H2SO4 solution of unknown concentration requires 22.87 mL of a 0.158 M KOH solution to reach the equivalence point. What is the concentration of the unknown H2SO4 solution?

9.03 * 10-2 M H2SO4

Treatment of gold metal with BrF3 and KF produces Br2 and KAuF4, a salt of gold. Identify the oxidizing agent and the reducing agent in this reaction. Find the mass of the gold salt that forms when a 73.5 g mixture of equal masses of all three reactants is prepared.

Br is the oxidizing agent, Au is the reducing agent, 38.8 g KAuF4

Mining companies use this reaction to obtain iron from iron ore: Fe2O3(s) + 3 CO(g) S2 Fe(s) + 3 CO2(g) The reaction of 167 g Fe2O3 with 85.8 g CO produces 72.3 g Fe. Determine the limiting reactant, theoretical yield, and percent yield.

CO is the limiting reagent, since it only produces 114 g Fe. Therefore, 114 g Fe is the theoretical yield: percentage yield = 63.4% yield

A solution contains one or more of the following ions: Ag+, Ca2+ , and Cu2+. When you add sodium chloride to the solution, no precipitate forms. When you add sodium sulfate to the solution, a white precipitate forms. You filter off the precipitate and add sodium carbonate to the remaining solution, producing another precipitate. Which ions were present in the original solution? Write net ionic equations for the formation of each of the precipitates observed.

Ca2+ and Cu2+ present in the original solution. Net ionic for first precipitate: Ca2+(aq) + SO4 2-(aq)->CaSO4(s) Net ionic for second precipitate: Cu2+(aq) + CO3 2-(aq)->CuCO3(s)

Write complete ionic and net ionic equations for each reaction. (a) 3 SrCl2(aq) + 2 Li3PO4(aq)-->Sr3(PO4)2(s) + 6 LiCl(aq) (b) HC2H3O2(aq) + KOH(aq)-->H2O(l) + KC2H3O2(aq)

Complete ionic equation: 3 Sr2+(aq) + 6 Cl-(aq) + 6 Li+(aq) + 2 PO4 3-(aq) -->Sr3(PO4)2(s) + 6 Li+(aq) + 6 Cl-(aq) Net ionic equation: 3 Sr2+(aq) + 2 PO4 3-(aq) -->Sr3(PO4)2(s) Complete ionic equation: HC2H3O2(aq) + K+(aq) + OH-(aq)-->H2O1l2 + K+ 1aq2 + C2H3O2 - 1aq2 Net ionic equation: HC2H3O2(aq) + OH -(aq)-->H2O(l) + C2H3O2-(aq)

Ammonia can also be synthesized by the reaction: 3 H2(g) + N2(g) S2 NH3(g) What is the theoretical yield of ammonia, in kg, that we can synthesize from 5.22 kg of H2 and 31.5 kg of N2 ?

H2 is the limiting reagent, since it produces the least amount of NH3. Therefore, 29.4 kg NH3 is the theoretical yield.

Write an equation for the precipitation reaction that occurs (if any) when solutions of potassium carbonate and nickel(II) chloride are mixed.

K2CO3(aq) + NiCl2(aq) --> NiCO3(s) + 2KCl(aq)

Write balanced molecular and net ionic equations for the reaction between hydrobromic acid and potassium hydroxide.

Molecular: HBr(aq) + KOH(aq)->H2O(l) + KBr(aq) Net ionic: H+(aq) + OH -(aq)->H2O(l)

The nitrogen in sodium nitrate and in ammonium sulfate is available to plants as fertilizer. Which is the more economical source of nitrogen, a fertilizer containing 30.0% sodium nitrate by weight and costing $9.00 per 100 lb or one containing 20.0% ammonium sulfate by weight and costing $8.10 per 100 lb?

NaNO3 is more economical

Write an equation for the precipitation reaction that occurs (if any) when solutions of sodium nitrate and lithium sulfate are mixed.

NaNO3(aq) + Li2SO4(aq) --> NO REACTION

Use oxidation states to identify the element that is oxidized and the element that is reduced in the following redox reaction. Mg(s) + 2 H2O(l)-->Mg(OH)2 (aq) + H2 (g)

Since Mg increased in oxidation state, it was oxidized. Since H decreased in oxidation state, it was reduced

Ammonia, NH3 , can be synthesized by the reaction: 2 NO(g) + 5 H2(g) S2 NH3(g) + 2 H2O(g) Starting with 86.3 g NO and 25.6 g H2 , find the theoretical yield of ammonia in grams.

Since NO makes the least amount of product, it is the limiting reactant, and the theoretical yield of ammonia is 49.0 g.

We can obtain titanium metal from its oxide according to the following balanced equation: TiO2(s) + 2 C(s) STi(s) + 2 CO(g) When 28.6 kg of C reacts with 88.2 kg of TiO2 , 42.8 kg of Ti is produced. Find the limiting reactant, theoretical yield (in kg), and percent yield.

Since TiO2 makes the least amount of product, it is the limiting reactant, and 52.9 kg Ti is the theoretical yield. 80.9%

Sulfur and fl uorine react to form sulfur hexafl uoride: S(s) + 3 F2(g) -> SF6(g) If 50.0 g S is allowed to react as completely as possible with 105.0 g F2(g), what mass of the excess reactant is left? a) 20.5 g S c) 45.7 g F2 c) 15.0 g S d) 36.3 g F2

a

What mass (in grams) of Mg(NO3)2 is present in 145 mL of a 0.150 M solution of Mg(NO3)2 ? a) 3.23 g b) 0.022 g c) 1.88 g d) 143 g

a

Assign an oxidation state to each atom in each element, ion, or compound. (a) Cl 2 (b) Na+ (c) KF (d) CO 2 (e) SO4 2- (f) K 2 O 2

a) 0 b) +1 c) 0 d) 0 e) -2 f) 0

Determine whether each reaction is an oxidation-reduction reaction. For each oxidation-reduction reaction, identify the oxidizing agent and the reducing agent. (a) 2 Mg(s) + O2 (g)->2 MgO(s) (b) 2 HBr(aq) + Ca(OH)2 (aq)->2 H2O(l) + CaBr2(aq) (c) Zn(s) + Fe2+ (aq)->Zn2+ (aq) + Fe(s)

a) Oxidizing agent: O2 Reducing agent: Mg b) none c) Oxidizing agent: Fe2+ Reducing agent: Zn

What is the oxidation state of Cr in each compound? a. CrO b. CrO3 c. Cr2O3

a. +2 b. +6 c. +3

What is the molarity of NO3 - in each solution? a. 0.150 M KNO3 b. 0.150 M Ca(NO3)2 c. 0.150 M Al(NO3)3

a. 0.150 M NO 3 - b. 0.300 M NO 3 - c. 0.450 M NO 3 -

Calculate the molarity of each solution. a. 3.25 mol of LiCl in 2.78 L solution b. 28.33 g C6H12O6 in 1.28 L of solution c. 32.4 mg NaCl in 122.4 mL of solution

a. 1.17 M LiCl b. 0.123 M C6H12O6 c. 0.00453 M NaCl

Complete and balance each gas-evolution equation. a. HBr(aq) + NiS(s) -> b. NH4I(aq) + NaOH(aq) -> c. HBr(aq) + Na2S(aq) -> d. HClO4(aq) + Li2CO3(aq) ->

a. 2 HBr(aq) + NiS(s)hH2->(g) + NiBr2(aq) b. NH4I(aq) + NaOH(aq)-> H2O(l) + NH3(g) + NaI(aq) c. 2 HBr(aq) + Na2S(aq)->hH2S(g) + 2 NaBr(aq) d. 2 HClO4(aq) + Li2CO3(aq)-> H2O(l) + CO2(g) + 2 LiClO4(aq)

Predict the products and write a balanced molecular equation for each reaction. If no reaction occurs, write "NO REACTION." a. HCl(aq) + Hg2(NO3)2(aq) S b. KHSO3(aq) + HNO3(aq) S c. aqueous ammonium chloride and aqueous lead(II) nitrate d. aqueous ammonium chloride and aqueous calcium hydroxide

a. 2 HCl(aq) + Hg2(NO3)2(aq)->Hg2Cl2(s) + 2 HNO3(aq) b. KHSO3(aq) + HNO3(aq)-> H2O(l) + SO2(g) + KNO3(aq) c. 2 NH4Cl(aq) + Pb(NO3)2(aq)-> PbCl2(s) + 2 NH4NO3(aq) d. 2 NH4Cl(aq) + Ca(OH)2(aq)->2 NH3(g) + 2 H2O(g) + CaCl2(aq)

Calculate the theoretical yield of the product (in moles) for each initial amount of reactants. Ti(s) + 2 Cl2(g) --> TiCl4(s) a. 4 mol Ti, 4 mol Cl2 b. 7 mol Ti, 17 mol Cl2 c. 12.4 mol Ti, 18.8 mol Cl2

a. 2 mol b. 7 mol c. 9.40 mol

For the reaction shown, calculate the theoretical yield of product (in grams) for each initial amount of reactants. 2 Al(s) + 3 Cl2(g) --> 2 AlCl3(s) a. 2.0 g Al, 2.0 g Cl2 b. 7.5 g Al, 24.8 g Cl2 c. 0.235 g Al, 1.15 g Cl2

a. 2.5 g b. 31.1 g c. 1.16 g

For each of the acid-base reactions, calculate the mass (in grams) of each acid necessary to completely react with and neutralize 4.85 g of the base. a. HCl(aq) + NaOH(aq) --> H2O(l) + NaCl(aq) b. 2 HNO3(aq) + Ca(OH)2(aq) -->2 H2O(l) + Ca(NO3)2(aq) c. H2SO4(aq) + 2 KOH(aq) --> 2 H2O(l) + K2SO4(aq)

a. 4.42 g HCl b. 8.25 g HNO3 c. 4.24 g H2SO4

Calculate how many moles of NO2 form when each quantity of reactant completely reacts. 2 N2O5 (g) --> 4 NO2(g) + O2 (g) a. 2.5 mol N2O5 b. 6.8 mol N2O5 c. 15.2 g N2O5 d. 2.87 kg N2O5

a. 5.0 mol NO2 b. 14. mol NO2 c. 0.281 mol NO2 d. 53.1 mol NO2

For each of the reactions, calculate the mass (in grams) of the product that forms when 3.67 g of the underlined reactant completely reacts. Assume that there is more than enough of the other reactant. a. Ba(s) + Cl2(g) -> BaCl2(s) b. CaO(s) + CO2(g) --> CaCO3(s) c. 2 Mg(s) + O2(g) --> 2 MgO(s) d. 4 Al(s) + 3 O2(g) --> 2 Al2O3(s)

a. 5.56 g BaCl2 b. 6.55 g CaCO3 c. 6.09 g MgO d. 6.93 g Al2O3

Hydrobromic acid dissolves solid iron according to the reaction: Fe(s) + 2 HBr(aq) --> FeBr2(aq) + H2(g) What mass of HBr (in g) do you need to dissolve a 3.2 g pure iron bar on a padlock? What mass of H2 would the complete reaction of the iron bar produce?

a. 9.3 g HBr, 0.12 g H2

Assign oxidation states to each atom in each element, ion, or compound. a. Ag b. Ag+ c. CaF2 d. H2S e. CO3 2- f. CrO4 2-

a. Ag: 0 b. Ag: +1 c. Ca: +2, F: -1 d. H: +1, S: -2 e. C: +4, O: -2 f. Cr: +6, O: -2

Write balanced complete ionic and net ionic equations for each reaction. a. HCl(aq) + LiOH(aq) -> H2O(l) + LiCl(aq) b. MgS(aq) + CuCl2(aq) -> CuS(s) + MgCl2(aq) c. NaOH(aq) + HC2H3O2(aq) -> H2O(l) + NaC2H3O2(aq) d. Na3PO4(aq) + NiCl2(aq) -> Ni3(PO4)2(s) + NaCl(aq)

a. Complete: H+(aq)+Cl-(aq)+Li+(aq)+ OH-(aq)->H2O(l)+Li+(aq)+Cl-(aq) Net: H+(aq)+OH-(aq)->H2O(l) b. Complete: Mg2+(aq)+S2-(aq)+Cu2+(aq)+2Cl-(aq)-> CuS(s)+Mg2+(aq)+2Cl-(aq) Net: Cu2+(aq)+S2-(aq)->CuS(s) c. Complete: Na+(aq)+OH-(aq)+HC2H3O 2 ( aq )->H 2 O(l)+Na+(aq)+C2H3O2-(aq) Net: OH-(aq)+HC2H3O2(aq)-> H2O(l)+C2H3O2-(aq) d. Complete: 6 Na+(aq)+2PO4 3-(aq)+3Ni2+(aq)+6Cl-(aq)->Ni3(PO4)2(s)+6Na+(aq)+6Cl-(aq) Net: 3 Ni2+(aq) + 2 PO4 3-(aq)->Ni3(PO4)2(s)

Complete and balance each acid-base equation. a. H2SO4(aq)+ Ca(OH)2(aq) -> b. HClO4(aq) + KOH(aq) -> c. H2SO4(aq) + NaOH(aq) ->

a. H2SO4(aq) + Ca(OH)2(aq)->2 H2O(l) + CaSO4(s) b. HClO4(aq) + KOH(aq)->H2O(l) + KClO4(aq) c. H2SO4(aq) + 2 NaOH(aq)-> 2 H2O(l) + Na2SO4(aq)

Consider the reaction: 2 NO(g) + 5 H2 (g) -> 2 NH3 (g) + 2 H2O(g) A reaction mixture initially contains 5 moles of NO and 10 moles of H2. Without doing any calculations, determine which set of amounts best represents the mixture after the reactants have reacted as completely as possible. Explain your reasoning. a. 1 mol NO, 0 mol H2, 4 mol NH3, 4 mol H2O b. 0 mol NO, 1 mol H2, 5 mol NH3, 5 mol H2O c. 3 mol NO, 5 mol H2, 2 mol NH3, 2 mol H2O d. 0 mol NO, 0 mol H2, 4 mol NH3, 4 mol H2O

a. Since the mol ratio of H2 to NO is 5:2, the 10 mol of H2 will require 4 mole NO, and H2 is the limiting reactant. This eliminates answers b and c. Since there is excess NO, this eliminates d, leaving answer a.

Determine whether or not each reaction is a redox reaction. For all redox reactions, identify the oxidizing agent and the reducing agent. (a) 2 Li(s) + Cl2 (g)->2 LiCl(s) (b) 2 Al(s) + 3 Sn2+ (aq)->2 Al3+ (aq) + 3 Sn(s) (c) Pb(NO3)2 (aq) + 2 LiCl(aq)->PbCl2(s) + 2 LiNO3(aq) (d) C(s) + O2 (g)>CO2 (g)

a. This is a redox reaction in which Li is the reducing agent (it is oxidized) and Cl2 is the oxidizing reagent (it is reduced). b. This is a redox reaction in which Al is the reducing agent and Sn2+ is the oxidizing agent. c. This is not a redox reaction because no oxidation states change. d. This is a redox reaction in which C is the reducing agent and O2 is the oxidizing agent.

Predict whether each compound is soluble or insoluble. (a) NiS (b) Mg3(PO4)2 ( c) Li2CO3 (d) NH4Cl

a. insoluble b. insoluble c. soluble d. soluble

Determine whether each reaction is a redox reaction. For each redox reaction, identify the oxidizing agent and the reducing agent. a. 4 Li(s) + O2(g) -> 2 Li2O(s) b. Mg(s) + Fe2+(aq) -> Mg2+(aq) + Fe(s) c. Pb(NO3)2(aq) + Na2SO4(aq) -> PbSO4(s) + 2 NaNO3(aq) d. HBr(aq) + KOH(aq) -> H2O(l) + KBr(aq)

a. redox reaction, oxidizing agent: O2, reducing agent: Li b. redox reaction, oxidizing agent: Fe2+, reducing agent: Mg c. not a redox reaction d. not a redox reaction

Determine whether each compound is soluble or insoluble. If the compound is soluble, list the ions present in solution. a. AgNO3 b. Pb(C2H3O2)2 c. KNO3 d. (NH4)2 S

a. soluble Ag+, NO3- b. soluble Pb2+, C2H3O2- c. soluble K+, NO3 - d. soluble NH4+, S2

For each compound (all water soluble), would you expect the resulting aqueous solution to conduct electrical current? a. CsCl b. CH3OH c. Ca(NO2)2 d. C6H12O6

a. yes b. no c. yes d. no

Identify the correct balanced equation for the combustion of propane ( C3H8 ). a) C3H8(g) --> 4 H2(g) + 3 C(s) b) C3H8(g) + 5 O2(g) --> 4 H2O(g) + 3 CO2(g) c) C3H8(g) + 3 O2(g) --> 4 H2O(g) + 3 CO2(g) d) 2 C3H8(g) + 9 O2(g) --> 6 H2CO3(g) + 2 H2(g)

b

Sodium and chlorine react to form sodium chloride: 2 Na(s) + Cl2(g) --> 2 NaCl(s) What is the theoretical yield of sodium chloride for the reaction of 55.0 g Na with 67.2 g Cl2 ? a) 1.40 * 102 g NaCl b) 111 g NaCl c) 55.4 g NaCl d) 222 g NaCl

b

Sodium reacts with water according to the reaction: 2 Na(s) + 2 H2O(l) --> 2 NaOH(aq) + H2(g) Identify the oxidizing agent. a) Na(s) b) H2O(l) c) NaOH(aq) d) H2(aq)

b

What is the net ionic equation for the reaction that occurs when aqueous solutions of KHCO3 and HBr are mixed? a) K+(aq) + C2H3O2 -(aq) --> KC2H3O2(s) b) H+(aq) + HCO3 -(aq) --> CO2(g) + H2O(l) c) H+(aq) + OH-(aq) --> H2O(l) d) None of the above because no reaction occurs

b

What volume of a 1.50 M HCl solution should you use to prepare 2.00 L of a 0.100 M HCl solution? a) 0.300 L b) 0.133 L c) 30.0 L d) 2.00 L

b

Determine whether or not each reaction is a redox reaction. If the reaction is a redox reaction, identify which element is oxidized and which is reduced. (a) Hg2(NO3)2 (aq) + 2 KBr(aq)-->Hg2Br2 (s) + 2 KNO3(aq) (b) 4 Al(s) + 3 O2 (g)-->2 Al2O3 (s) (c) CaO(s) + CO2 (g)-->CaCO3 (s)

b. Reaction b is the only redeox reaction. Al is oxidized and O is reduced.

A 25.0 mL sample of a 1.20 M potassium chloride solution is mixed with 15.0 mL of a 0.900 M barium nitrate solution and this precipitation reaction occurs: 2 KCl(aq) + Ba(NO3)2(aq) -> BaCl2(s) + 2 KNO3(aq) The solid BaCl2 is collected, dried, and found to have a mass of 2.45 g. Determine the limiting reactant, the theoretical yield, and the percent yield.

barium nitrate, 2.81g Ba(NO 3 ) 2 , 87.1%

Potassium iodide reacts with lead(II) nitrate in the following precipitation reaction: 2 KI(aq) + Pb(NO3)2(aq) --> 2 KNO3(aq) + PbI2(s) What minimum volume of 0.200 M potassium iodide solution is required to completely precipitate all of the lead in 155.0 mL of a 0.112 M lead(II) nitrate solution? a) 348 mL b) 86.8 mL c) 174 mL d) 43.4 mL

c

What is the molarity of a solution containing 55.8 g of MgCl2 dissolved in 1.00 L of solution? a) 55.8 M b) 1.71 M c) 0.586 M d) 0.558 M

c

What is the net ionic equation for the reaction that occurs when aqueous solutions of KOH and HNO3 are mixed? a) K+(aq) + NO3 -(aq) S KNO3(s) b) NO3 - (aq) + OH-(aq) S NO3OH(s) c) H+(aq) + OH-(aq) S H2O(l) d) None of the above because no reaction occurs.

c

Manganese(IV) oxide reacts with aluminum to form elemental manganese and aluminum oxide: 3 MnO2 + 4 Al--> 3 Mn + 2 Al2O3 What mass of Al is required to completely react with 25.0 g MnO2 ? a) 7.76 g Al b) 5.82 g Al c) 33.3 g Al d) 10.3 g Al

d

Which solution will form a precipitate when mixed with a solution of aqueous Na2CO3 ? a) KNO3(aq) b) NaBr(aq) c) NH4Cl(aq) d) CuCl2(aq)

d

Aspirin can be made in the laboratory by reacting acetic anhydride ( C4H6O3 ) with salicylic acid ( C7H6O3 ) to form aspirin ( C9H8O4 ) and acetic acid ( C2H4O2 ). The balanced equation is C4H6O3 + C7H6O3-> C9H8O4 + C2H4O2 In a laboratory synthesis, a student begins with 3.00 mL of acetic anhydride (density = 1.08 g>mL) and 1.25 g of salicylic acid. Once the reaction is complete, the student collects 1.22 g of aspirin. Determine the limiting reactant, theoretical yield of aspirin, and percent yield for the reaction.

limiting reactant: C7H6O3, theoretical yield: 1.63 g C9H8O4, percent yield: 74.8%

Urea ( CH4N2O ) is a common fertilizer that is synthesized by the reaction of ammonia ( NH3 ) with carbon dioxide: 2 NH3(aq) + CO2(aq) --> CH4N2O(aq) + H2O(l) In an industrial synthesis of urea, a chemist combines 136.4 kg of ammonia with 211.4 kg of carbon dioxide and obtains 168.4 kg of urea. Determine the limiting reactant, theoretical yield of urea, and percent yield for the reaction.

limiting reactant: NH3 , theoretical yield: 240.5 kg CH4N2O, percent yield: 70.01%

Lead ions can be precipitated from solution with KCl according to the reaction: Pb2+(aq) + 2 KCl(aq) --> PbCl2(s) + 2 K+(aq) When 28.5 g KCl is added to a solution containing 25.7 g Pb2+ , a PbCl2 precipitate forms. The precipitate is filtered and dried and found to have a mass of 29.4 g. Determine the limiting reactant, theoretical yield of PbCl2, and percent yield for the reaction

limiting reactant: Pb2+, theoretical yield: 34.5 g PbCl2, percent yield: 85.3%