Honors Chemistry Final Exam

Study Guide 2014-2015Name: ______P:_____

The final exam will consist of two parts. Part one will be a lab practical worth 40 points. Part two will be a series of calculations/ concepts worth 60 points. You will be working with a partner during the lab practical assigned based on current overall averages.

Lab Practical- Tuesday, June 16

You and your partner will complete one of two lab experiences listed below. You will submit one lab report to be completed in class for scoring. All aspects of good lab technique will be assessed along with your written lab report. 40 points.

Lab Experiences

  • Determination of Molar Mass of Butane using Gas Law Equations
  • Stoichiometry- Molar Ratios in a Chemical Reaction

Chemistry Calculations and Concepts- Thursday, June 18

Part A. Short stoichiometry questions involving calculations. 7.5 points.

Mass – moles

  • How many moles are contained in 100.0 g of H2SO4?

Moles – mass

  • What is the mass of 2.5 moles of H2O?

Mass – volume

  • How many liters of CO2 gas can be produced from 22 grams of dry ice?

Empirical and Molecular formulas

  • The empirical formula of a compound is NO2. Its molecular mass is 96 g/mol. What is the molecular formula of the compound?

Percent composition

  • What is the percent by mass of carbon in H2CO3?

Part B. Predict the outcome and balance chemical equations. 7.5 points.

Solid magnesium is placed in a solution of copper (II) sulfate.

Solid sodium is placed in a solution of zinc nitrate.

A solution of silver nitrate is added to sodium chloride solution.

A solution of lead nitrate is added to a sodium hydroxide solution.

Methane (CH4) is burned in air.

Solutions of nitric acid and sodium hydroxide are mixed.

Part C. Atomic Theory and Structure. 10 points.

Element

/

Atomic Number

/

Mass Number

/

Number of Protons

/

Number of Neutrons

/

Number of Electrons

Carbon

11

35

Determine the electron configuration of an atom of Titanium.

What is the element Bromine’s most common ion? Determine the ion’s electron configuration.

What is the element Magnesium’s most common ion? Determine the ion’s electron configuration.

What is the difference between an ion and an isotope of a particular element? Determine two possible isotopes of carbon and indicate the number of subatomic particles (electrons, protons, and neutrons) of each isotope.

Ion = / Isotope =

Two Possible Isotopes of Carbon

Isotopes
No. of Electrons
No. of Protons
No. of Neutrons

Part D. 6 questions with multiple parts you select one stoichiometry problem and two others to answer completely. 35 points total.

  1. Stoichiometry Problem
  2. Stoichiometry Problem
  3. Gas Laws – Ideal Gas Law, Combined Gas Law, Dalton’s Law
  4. Equilibrium Problem involving Q
  5. Solutions- Freezing Pt. Depression
  6. Solution Stoichiometry involving dilutions

Stoichiometry- What mass of lead (II) iodide will be produced when 16.4g of lead (II) nitrate is added to 28.5g of potassium iodide?

Pb(NO3)2 is the LR

22.83 g PbI2 produced

Solutions- Formalin is an aqueous solution of formaldehyde, HCHO, used as a preservative for biological specimens. How many grams of formaldehyde must be used to prepare 2.5 L of 12.3 M formalin?

922.5 g of Formaldehyde needed

Solutions- Calculate the freezing point and the boiling point of a solution that contains 15.0 g of urea (CH4N2O) in 250 g of water. Urea is a covalently bonded compound.

Skip

Solution Stoichiometry- Acid rain results from the reaction of nitrogen dioxide with water in the air.

3NO2 (g) + H2O (l)  2HNO3 (aq) + NO(g)

At STP, how many liters of NO2 gas are required to produce 0.275 L of 0.400 M HNO3?

3.70 L NO2 gas required

Equilibrium-

a. Write the equilibrium expression for the reaction below.

2CO (g) + O2 (g)  2CO2 (g)

b. Determine the value for Keq given the equilibrium concentrations of the following substances:

[CO] = 2.0 M

[O2] = 1.5 MKeq = 1.5

[CO2] = 3.0 M

c.For the reaction

CO (g) + H2O (g)  H2 (g) + CO2 (g)

Keq = 5.10 at 527oC. If [CO] = 0.15 M, [H2O] = 0.25 M, [H2] = 0.42 M, and [CO2] = 0.37 M, calculate Q and determine how the reaction will proceed.

Q = 4.14Q< Keq, therefore, reaction shifts to the right to achieve equilibrium.

Gas Laws

a. Chlorine gas, Cl2, is used to purify the water in swimming pools. How many moles of chlorine gas are in a 7.00 L tank if the gas has a pressure of 865 mmHg and a temperature of 240C?

n = 0.327 moles Cl2

b. What is the molar mass of a gas if a 2.21 g sample occupies a volume of 0.425 L at STP?

116.3 g/mol

c. Limestone (CaCO3) reacts with HCl to produce aqueous calcium chloride and carbon dioxide gas.

i. Determine the balanced chemical reaction.

ii. How many liters of carbon dioxide are produced at 752 mmHg and 240C from a 25.0 g

sample of limestone?

CaCO3 + 2 HCl  H2O + CO2 + CaCl2

V = 6.16 L

Acids and Base

  1. Label the following in the equation below:

  1. Acid
  2. Base
  3. Conjugate Acid
  4. Conjugate Base

HC2H3O2 + H2O  C2H3O2- + H3O+

Acid Base Base Acid

  1. Indicate the name, pH, and if the following solutions are acids or bases.

Substance / Name / pH / Acid or Base?
0.100 M HCl / Hydrochloric acid / 1.0 / Acid
0.100 M NaOH / Sodium Hydroxide / 13 / Base
0.055 M HNO3 / Nitric Acid / 1.3 / Acid
0.75 M Ca(OH)2 / Calcium Hydroxide / 13.8 / Base