Final Review 12/5/24

Kinetics

100

E

200

If the rate of concentration change for F₂ is –0.281 M/s, what is the rate of concentration change for chlorine trifluoride, ClF₃?

Cl₂ (g) + 3 F₂ (g) → 2 ClF₃ (g)

0.187M/sec.

300

Given the reaction mechanism below

H₂O₂ + I^-  → H₂O + IO^-  (slow)

H₂O₂ + IO^- → H₂O + O₂ + I^- (fast)

Identify the reactants, products, intermediates, and catalyst of the reaction

Reactants: H₂O₂

Products: H₂O, O₂

Intermediates: IO^-

Catalyst: I^-

400

Given the reaction mechanism below

H₂O₂ + I^-  → H₂O + IO^-  (slow)

H₂O₂ + IO^- → H₂O + O₂ + I^- (fast)

What is the proposed mechanism for the elementary steps above.

r = k [H₂O₂] [ I^-]

Solutions

100

What is the osmotic pressure at 30 °C of a solution

of 1.68 M NaI?

83.5 atm

200

Rank the following in terms of increasing boiling point

1.0m C₂H₆, 1.0m NaBr, .5m C₄H₁₀, 1m CaBr₂

lowest: C₄H₁₀ ,  C₂H₆ , NaBr, CaBr₂

300

0.75 moles of sodium chloride is dissolved in 225 g water. What is the change and new boiling point of the solution compared to water? For water Kb = 0.512 °C/m and Kf = 1.86 °C/m. Assume ideal behavior for the solute.

Change is 3.4°C

Boiling point of solution is 103.4°C

Equilibrium

100

Given the following reaction, determine the  K_c expression.

2HBr(g) →  H₂(g) + Br₂(g)

K_c= [Br₂] [H₂]/ [HBr]²

200

For the following problems determine the new value of K_c of this reaction: 3NO  → N₂O + NO_2.   K_c= 24.48

(a) 6NO(g)  → 2 N2O(g) + 2 NO2(g)
(b) 3/2NO(g) → 1/2 N₂O 1/2NO₂ 

(c) NO₂ + N₂O → 3NO

a. K_c=599.27

b. K_c= 4.95

c. K_c = 0.041

300

 If the Kc of the reaction 2NO₂ (aq) ⇌ N₂O₄ (aq) is 9.2*10^-7, what is the value of Kp.

Kp = 3.8 * 10^-8

400

• Given the reaction N₂ (g)+ 3H₂ (g) ⇌ 2NH₃ (g)

• Initially [N₂]= 100.0M, [H₂]= 300.0 M

• At equilibrium [NH₃]= 10.0 M

• What is Kc?

K_c= 2,707.5

500

The reaction A(s) + 2B (g) ⇌ C(g) + D(l): Le Chatelier

• Temperature is decreased. (Reaction is endothermic)

• More D is added to the reaction

• More B is added to the reaction 

• The volume is reduced

• The pressure is increased

• A catalyst is added to the reaction

A. Left

B. Nothing

C. right

D. Right

E. Right

F. Right

Nuclear Chemistry and other

100

Write a nuclear reaction showing:                           

(a) electron emission by 14C 

(b) positron emission by 8B 

                                   

    

(a) ¹⁴₆C→ ⁰_-1e+¹⁴₇N

 (b) ⁸₅B→⁰₁e+⁸₄Be                

    

200

Write a nuclear reaction showing:

(c) electron capture by 125I 

(d) alpha emission by 210Rn

(c) ¹²⁵₅₃I+ ⁰_-1e→¹²⁵₅₂Te

(d) ²¹⁰₈₆Rn→⁴₂He+ ²⁰⁶₈₄Po

                                   

    

300

Consider the reaction: COCl₂(g) ⇌ CO(g) + Cl₂(g) Kc = 2.19x10^-10at 100oC
(a) A container contains 4.50x10^-2M COCl₂, 1.1x10^-7M CO, and 2.25x10^-6M Cl₂.
Which direction (if any) will the reaction proceed.

Right

400

629.5⁰K

Acid/Bases

100

What is the pH of the following: 

a.0.0010MHBr(aq)   

b.025MNaOH(aq)

                               

a. pH = 3

b. pH= 12.40

200

What is the pH of the following? 

a.0.112M CsBrO(aq)

b.0.15M HCN

a. 10.85= pH

b. pH = 5.1

300

If you wanted to make a buffer with pH = 4, what would be a good acid/base conjugate pair?

Any with a PKa of around 4.

400

(a) What is the %ionization of 0.200M HN3(aq) (note: HN3 is hydrazoic acid). (b) Without doing a calculation, would 0.200M HF(aq) have a greater or smaller %ionization.          

                                   

A. 0.97%

B. Greater since HF has a larger Ka