F23 CHEM-1414 Final Exam Review Part 2

Chapter 6 (Quantum Mechanics)

100

Calculate the energy of a light emitted by a photon with a wavelength of 706 nanometers.

2.82 x 10^-19 J

200

Write the shorthand electron configuration of zirconium (Zr) and identify how many valence and core electrons zirconium has.

[Kr]5s²4d²

Core electrons = 36

Valence electrons = 4

300

Write the full electron configuration of V³⁺.

1s²2s²2p⁶3s²3p⁶3d²

400

Draw a 4p orbital (including charges) and list the following:

n = 

l = 

ml = 

angular nodes = 

radial nodes =

n = 4

l = 1

ml = -1, 0, 1 

angular nodes = 1

radial nodes = 2

500

Write the full electron configuration of copper, then draw the largest d orbital it occupies, showing all nodes and charges. Finally, draw the radial distribution graph of this orbital.

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s¹4d¹⁰

(+ 4d orbital drawing)

Chapter 7 (Molecular Structures)

100

What is the bond angle between two Hydrogen atoms in NH₃?

107^o

200

Is SeF₄ a polar or non-polar molecule?

Polar

(See-Saw M.G.)

300

How many lone pairs, sigma bonds, and pi bonds are present in SO₄^2-?

Lone pairs = 10

Sigma bonds = 4

Pi bonds = 2

400

Show all resonance structures of HCO₂^-

Great Drawing!

500

Draw the Lewis structure for XeCl₃^-. What is the electron geometry, molecular geometry, and hybridization of this compound? 

Electron geometry = Octahedral

Molecular geometry = T-shaped

Hybridization = sp³d²

Chapter 9 (Thermodynamics)

100

Calculate the kinetic energy of a 3.3 kg bowling ball moving at a speed of 13 m/s.

280 J

200

At 25 ^oC, ΔH_freezing is -56.12 kJ/mol, and ΔH_deposition is -403.3 kJ/mol. What is ΔH_condesation?

-347.2 kJ/mol

300

If the ΔH of the following reaction is -24.3 kJ/mol, how much heat is released if you react 27.3 g of LiOH with excess H₂SO₃?

H₂SO₃ + 2LiOH → Li₂SO₃ + 2H₂O

-13.9 kJ

400

A 12.5 g cube of cobalt is heated to a temperature of 78.4 ^oC and is then dropped into a 250mL container filled with water at 25 ^oC. What is the final temperature of the cobalt? (C_{s, cobalt} = 0.419 J/g*C, C_{s, water} = 4.184 J/g*C)

25.3 ^oC

500

2CuO(s) + 4HCl(g) → 2CuCl(s) + Cl₂(g) + 2H₂O(g)

Calculate the change in enthalpy of the previous redox reaction between CuO and HCl using the following reactions:

(1) CuO(s) + H₂(g) → Cu(s) + H₂O(g), ΔH = -85 kJ

(2) 2Cu(s) + Cl₂(g) → 2CuCl(s), ΔH = -274 kJ

(3) H₂(g) + Cl₂(g) → 2HCl(g), ΔH = -184 kJ

ΔH = -76 kJ

Chapter 10 (Entropy and Free energy)

100

Predict the sign of the entropy change for the reaction below. Briefly explain your reasoning.

CaCO₃ (s) → CaO (s) + CO₂ (g)

Entropy change is positive, because there are more moles of products than reactants, or because there is a gas in the products, but not the reactants.

200

What is the value of ΔG of the following reaction at 50 ^oC? Is the reaction spontaneous at this temperature?

SiCl₄ + 4H₂O → H₄SiO₄ + 4HCl

ΔH = -206.6 kJ/mol

ΔS = -137.9 J/mol*K

ΔG = -162.0 kJ/mol

Spontaneous

300

Below what temperature does the following reaction become nonspontaneous?

2HNO₃(aq) + NO(g) → 3NO₂(g) + H₂O(l)

ΔS = 287.5 J/mol*K

ΔH = 136.5 kJ/mol

474.8 K or 201.6 ^oC

400

C₄H₈(g) + 6O₂(g) → 4CO₂(g) + 4H₂O(l), ΔS = ?

Calculate the entropy for the combustion reaction of butane using the following reactions conducted at 25 ^oC:

(1) 2H₂(g) + O₂(g) → 2H₂O(g), S^o = -571 J/C

(2) C₄H₈(g) + H₂(g) → C₄H₁₀(g), S^o = -126 J/C

(3) 2C₄H₁₀(g) + 13O₂(g) → 8CO₂(g) + 10H₂O(l),    S^o = -5754 J/C

-2718 J/mol*^oC

500

What is the ΔS_rxn of the following reaction? Is the reaction favored thermodynamically?

Mg (s) + 2HCl (aq) → MgCl₂(aq) + H₂(g)

S^o Mg (s) = 32.7 J/mol*K

S^o HCl (aq) = -92.3 J/mol*K

S^o H₂ (g) = 130.5 J/mol*K

S^o MgCl₂ (aq) = -191.8 J/mol*K

ΔS_rxn = 90.6 J/mol*K

Favored because ΔS > 0

Chapter 11 (Rate Laws)

100

What is the purpose of a catalyst?

To reduce the activation energy of a reaction and increase the reaction rate.

200

Using the following reaction, if the rate of appearance of H₂O is 0.0034 M/s, what is the rate of disappearance of O₂?

C₃H₈ + 5O₂ → 4H₂O + 3CO₂

0.00425 M/s

300

Write the chemical reaction outlined by the following relationships.

[Fe(OH)₃]/Δt = -1/3[NaOH]/Δt =

= 1/3[NaCl]/Δt = -[FeCl₃]/Δt

FeCl₃ + 3NaOH → Fe(OH)₃ + 3NaCl

400

In the first two minutes of the following reaction, the concentration of H₂SO₄ decreased from 3.0 M to 2.3 M. What is the rate of appearance of H⁺ in M/s?

H₂SO₄ (aq) + Zn (s) → ZnSO₄ (aq) + 2H⁺ (aq)

0.012 M/s

500

Determine the rate law and the value of k for the following reaction using the data provided. 

S₂O₈^2- + 3I^- → 2SO₄^2- + I₃^-

   [S₂O₈^2-](M)          [I^-](M)          Initial Rate(M^-1s^-1)

0.30                  0.42                    4.54

0.44                  0.42                    6.65

0.44                  0.21                    3.33

Rate = 36 M^-1s^-1 [S₂O₈^2-]¹ [I⁻]¹

k = 36 M^-1s^-1