Redox Reactions
Reactions
Gases
Problem Solving
Solution Stoich
100
What is the oxidation state of carbon in CO3(2) ?
+4 page 183 quiz # 13
100
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
69 Mol O2 Problems by topic P 186 Answer book page 58
100
A sample of neon effuses from a container in 76 seconds. Thesame amount of an unknown noble gas requires 155 seconds. Identify the gas.
Kr 87Kg/mol Book Page 241 Q 87 soln manual page 92
100
What volume of a 1.50 M HCl solution should you use to prepare 2.00 L of a 0.100 M HCl solution?
0.133 L book quiz page 183 Q # 7
200
Sodium reacts with water according to the reaction: 2 Na(s) + 2 H2O(l) S 2 NaOH(aq) + H2(g) Identify the oxidizing agent
H2O(l) Book Page 183 Quiz # 14
200
Predict the products and write a balanced molecular equation for the reaction. aqueous ammonium chloride and aqueous calcium hydroxide
2NH4Cl(aq) + Ca(OH)2(aq) --> 2NH3 + 2H2O(l) +CaCl2 p 190 book Que. 109 soln. Manual p 74
200
If the volume in which a gas reaction takes place is INCREASED, what happens to pressure
Decreases According to Boyle's Law, the volume of a gas is inversely proportional to the pressure of a gas. Therefore, increasing the volume has the same effect as decreasing the pressure
200
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 P 190 Que 99 soln. manual p 73
200
Potassium iodide reacts with lead(II) nitrate in the following precipitation reaction: 2 KI(aq) + Pb(NO3)2(aq) S 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?
174 mL P 183 Book - quiz
300
Lead ions can be precipitated from solution with KCl according to the reaction: Pb2+(aq) + 2 KCl(aq) S 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% Book Q 49 page 188 soln manual p 65
300
A cylinder contains 28.5 L of oxygen gas at a pressure of 1.8atm and a temperature of 298 K. How much gas (in moles) is in the cylinder?
P39 book Q. 41 soln manual p 84
300
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.
Q 127 book page 191 soln manual p 77
300
Zinc(II) sulfide reacts with oxygen according to the reaction: ZnS(s) + O2(g) --> ZnO(s) + SO2(g) A reaction mixture initially contains 4.2 mol ZnS and 6.8 molO2. Once the reaction has occurred as completely as possible, what amount (in moles) of the excess reactant is left? Balance equation first
2 ZnS(s) + 3 O2(g) S 2 ZnO(s) + 2 SO2(g) - balanced 0.5 moles of O2 left (6.8 mol - 6.3 mol) Question # 43 Answer page 64
400
Is the following a redox reaction and if so who is oxidized and who is reduced and who is the reducing agent and who is the oxidizing agent. 2HBr(aq) +Ca(OH)2(aq) --> 2H2O + CaBr2(aq)
This is not a redox reaction Book page 181 4.18 b
400
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) + 2 NO3 -(aq) + 2 Na+(aq) + 2 Cl-(aq)h Hg2Cl2(s) + 2 Na+(aq) + 2 NO3-(aq) Net: Hg2 2+(aq) + 2 Cl-(aq)hHg2Cl2(s) book page 189 Q 81 soln manual p 70
400
Consider the chemical reaction: C(s) + H2O(g) S CO(g) + H2(g) How many liters of hydrogen gas are formed from the complete reaction of 15.7 g C? Assume that the hydrogen gas is collectedat a pressure of 1.0 atm and a temperature of 355 K.
38L Book P. 240 Q. # 71 soln Manual P 89
400
The air within a piston equipped with a cylinder absorbs 565 J of heat and expands from an initial volume of 0.10 L to a final volume of 0.85 L against an external pressure of 1.0 atm. What is the change in internal energy of the air within the piston?
53. 489 J Q. 53 book page 288 soln. manual p 107
400
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?
find Kg of CO2 in each reaction then add the 3 CO2 products to get total. 30.8 Kg CO2 p.
500
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.
This is a redox reaction. Au is reducing agent. BrF3 is oxidizing agent ( Au increases in Oxidation # and Br decreases) BrF3 is the oxidizing agent Au is reducing agent Q 117 page 191 soln manual page 75
500
late the enthalpy for this reaction: 2C(s) + H2(g) ---> C2H2(g) ΔH° = ??? kJ C2H2(g)+(5/2)O2(g)--->2CO2(g)+H2O(ℓ)ΔH°=-1299.5kJ C(s) + O2(g) ---> CO2(g) ΔH° = -393.5 kJ H2(g) + (1/2)O2(g) ---> H2O(ℓ) ΔH° = -285.8 kJ
a) first eq: flip it so as to put C2H2 on the product side b) second eq: multiply it by two to get 2C c) third eq: do nothing. We need one H2 on the reactant side and that's what we have 2CO2(g)+H2O(ℓ)->C2H2(g)+(5/2)O2(g) ΔH°=+1299.5 kJ 2C(s) + 2O2(g) ---> 2CO2(g) ΔH° = -787 kJ H2(g) + (1/2)O2(g) ---> H2O(ℓ) ΔH° = -285.8 kJ Examine what cancels: 2CO2 ⇒ first & second equation H2O ⇒ first & third equation (5/2)O2 ⇒ first & sum of second and third equation Add up ΔH values for our answer: +1299.5 kJ + (-787 kJ) + (-285.8 kJ) = +226.7 kJ
500
A 160.0 L helium tank contains pure helium at a pressure of1855 psi and a temperature of 298 K. How many 3.5 L helium balloons will the helium in the tank fill? (Assume an atmospheric pressure of 1.0 atm and a temperature of 298K.)
Q 113 book page 243 soln manual p 97
500
When 0.514 g of biphenyl (C12H10) undergoes combustion in a bomb calorimeter, the temperature rises from 25.8 !C to 29.4 !C.Find "Erxn for the combustion of biphenyl in kJ/mol biphenyl.The heat capacity of the bomb calorimeter, determined in a separate experiment, is 5.86 kJ/!C.
-6.3 * 103 kJ/mol book page 289 que. 73 soln manual page 110
500
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.)
3.1Kg CO2 P 190 book Answer soln. manual P 73