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Quiz #1 (1/27/14) One the board, you will see a sketch of the cell formed by Cd in Cd(NO 3 ) 2 and Cu in Cu(NO 3 ) 2 1.Which metal forms the anode of this.

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Presentation on theme: "Quiz #1 (1/27/14) One the board, you will see a sketch of the cell formed by Cd in Cd(NO 3 ) 2 and Cu in Cu(NO 3 ) 2 1.Which metal forms the anode of this."— Presentation transcript:

1 Quiz #1 (1/27/14) One the board, you will see a sketch of the cell formed by Cd in Cd(NO 3 ) 2 and Cu in Cu(NO 3 ) 2 1.Which metal forms the anode of this cell? ANSWER – Cadmium (Cd) 2.Write the cell notation for this cell. ANSWER – Cd | Cd 2+ || Cu 2+ | Cu 3.Calculate the overall cell potential for this cell. ANSWER - 0.34 – (-0.40) = +0.74 V Reduction Potentials: Cd 2+ + 2e -  Cd = -0.40V Cu 2+ + 2e -  Cu = 0.34V

2 Quiz 2 (1/29/14) 4.True or false: At chemical equilibrium, the rate of the forward reaction equals the rate of the reverse reaction. ANSWER - True

3 Quiz 2 (1/29/14 - continued) Questions 5 and 6 refer to the chemical reaction given here: CO(g) + 3H 2 (g) CH 4 (g) + H 2 O (g) 5.Write out the expression for the equilibrium constant (K eq ) ANSWER:[CH 4 ][H 2 O] [CO] [H 2 ] 3 6. If the value of K eq for this reaction is 5.5 x 10 -4, you will have more REACTANTS present at equilibrium.

4 Quiz 3 (1/31/14) 7.For the reaction: H 2 + I 2 2 HI (g), the concentrations at equilibrium are: [H 2 ] = 0.11 M, [I 2 ] = 0.11M, [HI] = 0.78M Calculate the value of K eq for this reaction to the nearest whole number. ANSWER: (.78) 2 = 50 (.11) (.11)

5 Quiz 3 (1/31/14 – continued) Given the same reaction: H 2 + I 2 2 HI 8.How does the system shift when hydrogen gas is added to the reaction? (To the left or to the right?)ANSWER: RIGHT 9.How does the system shift when hydrogen iodide is removed from the reaction? (To the left or to the right?) ANSWER: RIGHT

6 Quiz 4 (2/3/14) Given the exothermic reaction: C 2 H 4 (g) + Br 2 (g) C 2 H 4 Br 2 (g) How does the equilibrium shift (Left, Right, or None) when: 10. The temperature is increased - LEFT 11. The pressure is increased - RIGHT 12. A catalyst is added to the reaction - NONE

7 Quiz 5 (2/5/14) 13. A Bronsted-Lowry acid is defined as a proton DONOR. 14. Since Sulfuric acid (H 2 SO 4 ) has two acidic protons it is known as a(n) diprotic acid. 15. Can the chemical species HCO 3 -1 act as an acid, a base, or both?

8 Quiz 6 (2/7/14) 16. Write the formula for the conjugate base of HSO 4 -1.Answer: SO 4 -2 The acid/base reaction below is used for questions 17 and 18. HF (g) + H 2 O (l)  F - (aq) + H 3 O + (aq) What are the chemical formulas of the two acid species in the reaction above? Answer: HF and H 3 O + 19.Is nitric acid (HNO 3 ) a weak or a strong acid?

9 Quiz 7 (2/10/14) For the reaction: HCN (g) + OH - (aq) ?? 20 and 21. Write the chemical formulas of the products of this reaction. ANSWER: HCN + OH -  CN - + H 2 O 22.Which side (left or right) is favored at equilibrium? ANSWER – RIGHT (weaker acid and weaker base) 23.If a sample has a [H 3 O + ] = 2.5 x 10 -6 what is the value of the [OH - ] ? ANS: 1x10 -14 = (2.5x10 -6 )(OH - ) so, (OH - ) = 1x10 -14 / 2.5x10 -6 = 4x10 -9 M

10 Quiz 8 (2/12/14) You are given a sample of 1.75M NaOH. STRONG BASE!! 24.What is the [OH - ] of this sample? Answer: 1.75M 25.What is the [H 3 O + ] of this sample? Answer: 1x10 -14 / 1.75 = 5.71 x 10 -15 M 26.What is the pH of this sample? Answer: -log 5.71x10 -15 = 14.2


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