SEM2
Chemistry Second Semester Final Review sheet
Unit 6 part 1:
1. Be familiar with the definition of pressure and what factors increase pressure in a system.
2. Relate the kinetic molecular theory to the various gas laws.
3. Perform calculations using the 3 gas laws relating temperature, volume, and pressure.
Ex. A balloon is filled with 1.3L or Nitrogen gas at STP. The balloon is then taken to a
higher elevation where the pressure decreases to 0.72atm and the temperature is -5C. Find the
new volume of the balloon.
4. Understand the units of the Ideal Gas Constant (R).
5. Understand STP and the relationship between moles of a gas and volume of a gas at STP.
5. Perform stoichiometry calculations using the ideal gas equation and balanced chemical
reactions.
E.X. The reaction N 2(g) + 3H 2(g) -----------} 2NH 3(g) is performed at 35C and a pressure of 16atm. If we
start with 1.5L of N 2 , find the mass of NH 3 we can produce.
6. Convert units of pressure (atm, Pa, mmHg). For example: convert 135mmHg to atm.
Unit 6 part 2:
1. Be familiar with the following terms:
-Soluble
-Solution
-Suspension
-Colloid
-Electrolyte and non-electrolyte
-Absolute zero
2. Understand factors that increase solubility
3. Understand how a catalyst functions.
4. Be able to perform stoichiometric calculations using molarity, moles or even the ideal gas
equation.
E.X. NaCl (aq) + Ca(OH) 2(aq) ----------} NaOH (aq) + CaCl 2(aq)
If 30ml of 0.5M NaCl react with excess Ca(OH) 2 , find the mass of CaCl2 that can be produced.
E.X. what volume of 0.5M NaCl solution would be needed to react with 100g of Ca(OH) 2 in the
reaction above?
Unit 7 part 1:
1. Understand the difference between ionization and disassociation:
2. Be able to use a solubility chart to determine if a certain reaction will produce a precipitate
(Note: you do not have to memorize the solubility chart):
-EX: write the products of the reaction of (NH 4 ) 2 S + Cd(NO 3 ) 2 and determine if a
precipitate will form?
3. Write a net ionic equation:
-EX: If solutions of barium chloride and sodium sulfate are combined will a precipitate
form? If so write a net ionic equation
4. Understand what makes a strong and weak electrolyte.
Unit 7 part 2:
1. Be familiar with the properties of acids and bases:
2. Be familiar with the names of the following acids:
-HF -HNO 3 -H 2 SO 4 -HCl
-CH 3 COOH -HI -HBr
3. Understand the definition of the following:
-Arrhennius acids and bases:
-Bronsted-Lowry acids and bases
-Lewis acids and bases:
EX: Identify each acid and base:
HF + H 2 O F - + H 3 O +
H + + NH 3 NH 4 +
4. Know the strong and weak acids and bases:
5. Be familiar with conjugate acids and bases and understand their strength (i.e. a conjugate
base of a weak acid is strong and vice versa).
Unit 7 part 3
1. Be able to calculate pH or pOH if given the concentration:
-EX: Determine the pH of a 2.0*10 -2 M Sr(OH) 2 solution:
2. Be able to determine the [H3O+] and the [OH-] if given the molarity:
-EX: if a solution of HNO 3 has a concentration of 1.0*10 -4 M, find OH - and
H3O + concentrations:
3. Be able to calculate the H3O+ or OH- concentrations from the pH or pOH:
-EX: Find the [OH - ] and [H3O + ] of a solution with a pH of 9.3. And determine if it is basic
or acidic.
4. Be able to perform stoichiometry calculations for titrations:
-EX: Find the volume of 0.900M NaOH solution needed to fully titrate 55ml of a 1.5M
HNO 3 solution.
5. Understand the general process of titration, what is the end point, and what is an indicator
used for.
Unit 8
*1. Perform specific heat calculations:
EX: If 980 kJ of heat are added to 6.2L of water at 291K, what will its final temperature be?
(Specific heat of water is 4.18J/(g*K).
2. Be able to solve problems involving enthalpy change:
EX: Calculate the enthalpy of reaction for the following reaction using the data in provided
a) CaCO 3 (s) CaO(s) + CO 2 (g)
Ca + C + 3/2 O 2 CaCO 3 ΔH = -834 kJ/mol
Ca + ½ O 2 CaO ΔH = -233 kJ/mol
C + O 2 CO 2 ΔH = -395.8 kJ/mol
b) Combustion of glucose (C 6 H 12 O 6 )
6C + 3O 2 + 6H 2 C 6 H 12 O 6 ΔH = -3992.2 kJ/mol
C + O 2 CO 2 ΔH = -395.8 kJ/mol
H 2 + ½ O 2 H 2 O ΔH = -285.5 kJ/mol
3. Understand the difference between exothermic and endothermic reactions and explain how
the sign of ΔH indicates which one is which.
4. Understand entropy, enthalpy, and free energy, how they relate to each other, and what
each one means in an equation:
5. Perform free energy calculations:
EX: for the vaporization of Br(l) Br 2 (g), ΔH= 310.0kJ/mol. and ΔS = 93.0J/(mol.K). At what
temperature will this reaction be spontaneous?
Unit 9
1. Be familiar with the collision theory and conditions that speed up chemical reactions.
*2. Understand Ea and Ea’ and ΔE and be able to calculate each on a graph.
-Draw and label and energy diagram that depicts the following: ΔE forward = -10kJ/mol,
Ea’=40kJ/mol.
3. Understand how the presence of a catalyst speeds up chemical reactions:
4. Understand 5 factors that speed up reaction rate.
5. Be able to write rate laws:
EX: Use the table below to write the rate law for the equation of A + B C
[A] (M) [B] (M) Rate (M/s)
0.08 0.06 0.012
0.08 0.03 0.006
0.04 0.06 0.003
EX: for the following reaction: A + B C + D doubling the concentration of A quadruples the
rate of C formed if B is held constant. However, doubling B has no effect on the rate of C being
formed. Write a rate law:
Unit 10
1. Explain what is meant by chemical equilibrium and understand how to write an equilibrium
expression.
-EX: An equilibrium mixture of N 2 , O 2 , and NO gasses at 1500K is determined to consist of 6.4*10 -
3 mol/L of N 2 , 1.7*10 -3 mol/L of O 2 and 1.1*10 -5 mol/L of NO. What is the equilibrium constant?
2. Understand what changes in pressure, temperature and concentration will have on
equilibrium.
3. Understand what situations cause and equation to go to completion.
4. be familiar with the common ion effect.
5. Understand what solutions form buffers.
6. Be familiar with anion and cation hydrolysis and how to determine if a solution will be basic
or acidic:
-EX: Determine if the following will be basic or acidic:
0.5M KI 0.25M CaF 2 0.05M K 2 CO 3
7. Calculate Ksp :
-EX Calculate Ksp of lead (II) Chloride, PbCl 2 , which has a solubility of 1.0g/100g H2O at 20C:
8. Calculate solubility:
-EX: The Ksp for cadmium sulfide, CdS is 8.0*10 -27 , find its solubility.
Unit 11 part 1
1. Be able to assign oxidation numbers:
SO 4 2- SO 2 NO 3 -
2. Be familiar with the process of oxidation and reduction and what is the indication that each
has happened.
*3. Balance redox reactions:
EX: Sb 5+ + I- I 2 + Sb 3+
4. Be familiar with oxidizing and reducing agents and be able to relate the strength of one to the
other.
Unit 11 part 2
1. Understand the reaction of voltaic cell.
2. Know the following:
-Anode
-Cathode
3. Understand some uses of voltaic cells
4. be familiar with the uses of electrolytic cells.
5. Differentiate between voltaic and electrolytic cells.
6. Be able to draw a voltaic cell, determine the E o cell, and calculate the potential of the cell.
E.X. A cell voltaic cell consists of a copper electrode in a copper(II) chloride solution and a Tin
electrode in a Tin(IV)chloride solution.
Draw the cell, determine the anode and cathode (Use the table in the book), write each half
equation, and find the E o cell.
7. Understand what the products will be at the anode and cathode of an electrolytic cell.
E.X. an electrolytic cell consists of Liquid CaI2 electrolyte. Determine the products at the anode
and cathode and write the reaction that happens at each one.
Final Exam Practice Problems
Unit 6
1) A balloon has a volume of 4L and a pressure of 2.2atm. It is floated to a height of 20m and the volume
increases to 5.1L. Find the new pressure.
2) A container is at pressure of 0.89atm and a volume of 500ml and a temperature of 22C. It is heated to
55C and the volume is increased to 600ml. Find the new pressure.
3) What is the volume of 2.7moles of CH 4 gas at STP?
4) Find the volume of 0.500 moles of H 2 gas that occupies a volume of 2.7L at 25C and a pressure of 1
atm.
5) The reaction below is carried out at 20C and a pressure of 1.1 atm. If 2L of Hydrogen gas reacts with
excess oxygen, find the moles of water vapor produced.
H 2(g) + O 2(g) H 2 O (g)
6) Convert the following into atm:
a) 1.7*10 8 Pa
b) 920 mmHg
7) What is the molarity of 85g of NaOH dissolved in 50ml of water?
8) NaCl (aq) + Ba(NO 3 ) 2(aq) NaNO 3(aq) + BaCl 2(s)
25ml of 0.700M barium nitrate reacts with excess NaCl. Find the mass of sodium nitrate produced.
Unit 7
1) Write the products of the reaction of Na 2 SO 4 + Ba(NO 3 ) 2 and determine if a precipitate will form?
2) If solutions of Iron (II)nitrate and sodium carbonate are combined will a precipitate form? If so write
a net ionic equation
3) For the reaction below, label the acid and base and identify the conjugate acid and base:
NH 3 + H 2 O NH 4 + + OH -
4) Determine the pH of a 1.0*10 -4 M NaOH solution:
5) if a solution of HBr has a concentration of 1.0*10 -6 M, find OH - and H 3 O + concentrations:
6) Find the [OH - ] and [H 3 O + ] of a solution with a pH of 5.5.
7) Find the volume of a 2.7M HCl solution needed to fully titrate 20ml of a 1.5M NaOH solution.
Unit 8
1) You need 70.2 J to raise the temperature of 34.0g of ammonia (NH3) from 23.0 to 24.0C. Calculate the
specific heat of ammonia.
2) A reaction has ΔH= -356kJ and ΔS= -36J/K. Calcualte ΔG at 25C and confirm if the reaction is
spontaneous.
3) Find the Enthalpy of Formation of Methane gas (CH4) from its elements.
Use the following enthalpies of combustion:
C (s) + O 2 (g) CO 2 (g) ΔH 0 c = -393.5 kJ
H 2(g) + ½ O 2 (g) H 2 O (l) ΔH 0 c = -285.8 kJ
CH 4(g) + 2O 2(g) CO 2(g) + 2H 2 O (g) ΔH 0 c = -890.8 kJ
Unit 9
1) Identify the Ea, Ea’ and ΔH for the FORWARD AND REVERSE of the following reactions
2) Draw an energy diagram with Ea = 60 kJ and ΔH= -40kJ
3) A chemical reaction occurs as follows: A + 2B C. The following data was obtained about the
reaction:
Number Initial [A] Initial [B] Rate of formation of
C
1 0.2 M 0.2M 2.0*10 -4
2 0.4 M 0.2M 8.0*10 -4
3 0.4 M 0.4M 1.6*10 -3
Determine the rate law and calculate the value of the specific rate constant:
4) A reaction is found to occur in a 1 step mechanism according to the following reaction:
2A + B A 2 B. Write a rate law for the reaction.
5) In a certain reaction, A+ B C, doubling A doubles the rate and halving B reduces the rate by ¼.
Write the rate law for this reaction.
Unit 10
1) An equilibrium mixture of N 2 , H 2 , and NH 3 gasses at 1500K is determined to consist of 6.4*10 -3 mol/L of
N 2 , 2.2*10 -3 mol/L of H 2 and 7.1*10 -5 mol/L of NH 3 . What is the equilibrium constant?
2) Determine if the following will be basic or acidic:
-NaCl - BaF 2 - FeBr 2
3) Calculate Ksp of Iron (II) Carbonate, FeCO 3 , which has a solubility of 0.025g/100g H2O at 20C:
4) The Ksp for Zinc Sulfide, ZnS is 2.3*10 -14 , find its solubility.
Unit 11
1) Assign oxidation numbers to the following
- N 2 -HClO -Na + -BaCl 2
2) For the reactions below, determine if they are redox and if they are, which species got oxidized and
which got reduced.
a) N 2 + O 2 N 2 O 2
b) NaCl + H 2 SO 4 Na 2 SO 4 + HCl