General Chemistry Answers

 Show all work out and answer questions a, b,and c!

The Y^- ion reacts with water to form HY and hydroxide ion, as shown in the following equation.

Y^- (aq) + H2O (l) ⇌ HY (aq) + OH^- (aq)

Given that [OH^-] is 1.77 x 10^-5 M in a 0.480 M solution of NaY, calculate each of the following:

(a) The value of K_b for the Y^- ion. 

(b) The value of K_a for HY. 

(c) Which acid, HZ or HY, is stronger? Justify your answer

A new weak acid, HG, has been synthesized. The a titration of 0.115g of HG requires 16.00 mL of 0.10 M KOH solution to reach the equivalence point.

(a) Write the dissociation equation for HG in water and its equilibrium expression (K_a). 

(b) Write the net ionic equation for the titration reaction.

Explain why the sodium sulphate solution becomes more concentrated during the electrolysis process.

2. Based from the phase diagrams of water and carbon dioxide, answer the following questions and justify your answers: 1. You have ice at 263 K (-10.0 oC) and 1.0 atm. What could you do to make the ice sublime? 2. A sample of dry ice (solid CO2) is cooled to 173 K (-100.0 oC), and is set on a table at room temperature (298 K; 25 oC). At what temperature is the rate of sublimation and deposition the same (assume that pressure is held constant at 1 atm)?

Using the standard reduction potentials, determine whether the following reactions are spontaneous under standard conditions:

A. Magnesium reducing chlorine to chloride ions

B. Silver reducing hydrogen ions to hydrogen

Analyze each cell reaction. Identify and write the half-reaction that occurs in the anode and in the cathode. Calculate the standard cell potential and describe the reaction whether it is spontaneous or nonspontaneous. Show your solution.

1. Li (s) + F2 (g) = Li+ (aq) + 2F- (aq)

2. Au3+ (aq) + Co (s) = Au (s) + Co2+ (aq)

3. 2 Al (s) + 3 i2 = 2 Al+3 (aq) + 6 i-1 (aq)

4. F2 (g) + 2Cl-1 (aq) = 2F-1 (aq) + Cl2 (g)

What is the concentration of free Ag⁺ in 0.034 M solution of [Ag(NH₃)₂]⁺, K_f = 1.7 x 10⁷? Report your answer as -1*log(free Ag⁺)

If 0.100 mole of NH₃ is added to 1.00 L of 2.00 x 10^-2 M solution of M²⁺, giving [M(NH₃)₆]²⁺and a free M²⁺ concentration of 0.001, what is pK_f for [M(NH₃)₆]²⁺?

Calculate the concentration of free Ni²⁺ that is present in equilibrium with 1.5 x10^-3 M [Ni(NH₃)₆²⁺ and 0.243 M NH₃.    [Ni(NH₃)]₆²⁺K_f = 1.8 x 10⁸ 

Give your concentration as p[Ni²⁺] (-log[Ni²⁺])

A 20.00-ml sample of aqueous oxalic acid, H.C.O., was titrated with a 0.09113-M solution of potassium permanganate, KMnO..

2MnO4 (ag) + 5H₂C₂O₁(ag) + 6H* (ag) 1000₂(g) + 2Mn²+ (aq) + 8H₂O

A volume of 23.24 ml was required to reach the end point. What is the molarity of axalic acid ?