Titrations/Buffers
A solution that contains a weak acid and its conjugate base in roughly equal concentrations is
What is a buffer?
1. Which of the following is in the correct order of standard state entropy?
I. Liquid water < gaseous water
II. Liquid water < solid water
III. NH3 < H2
What is I?
The equation for Gibbs free energy is
What is ΔG° = ΔH° – T ΔS° ?
Oxidation and Reduction can be remembered through the acryonym of.
What is OIL RIG ?
Electrolytic cells allow a process called
What is Electrolysis?
The solubility product for an insoluble salt with the formula MX2 is written as __________, where x is the molar solubility.
What is Ksp = 4x 3?
Determine ΔS for H2(g) + I2(g) --> 2HI(g) given the following information.
Substance S° (J/mol · K)
H2(g) 130.58
I2(g) 116.73
HI(g) 206.3
What is +165.29 J/mol · K?
The difference in the usage of energy between spontaneous and non spontaneous reactions is said to be
The two parts of oxidation and reduction are linked to what two parts of a voltaic cell?
What is anode and cathode? AN OX RED CAT
What is 𝑬𝒄𝒆𝒍𝒍 = 𝑬𝒄𝒆𝒍𝒍° − (𝑹 𝑻/𝒏 𝑭 )(𝐥𝐧 𝑸)
A solution of hydrochloric acid (HCl, 40.00 mL) was titrated to the equivalence point with 22.0 mL of 0.320 M sodium hydroxide. What was the concentration of the hydrochloric acid?
What is 0.178 M
In a spontaneous process, which of the following always increases?
What is the entropy of the universe?
Compute ΔG° for this reaction at 25 °C.
4 C2H6(g) → C8H18(g) + 3 H2(g)
Substance ΔGf° (kJ/mol rxn)
H2(g) 0
C2H6(g) -32.0
C8H18(g) +6.4
What is +134.4kJ/mol. ?
Methanol fuel cells use the following reaction. How many electrons are transferred in this redox reaction as written? 2CH3OH + 3O2 → 2CO2 + 3H2O?
What is 12 electrons?
What mass of lithium could be plated (in other words, turned into solid) from an aqueous solution of LiCl if 2.5 A run through the solution for 35 minutes in an electrolytic cell?
What is 0.38 𝑔 𝐿𝑖 ?
Calculate the pH of a solution that’s 0.65M in NaF and 0.75M in HF. (HF, Ka = 7.2 × 10–4 )?
What is 3.08?
A reaction with a low enthalpy of reaction value is not spontaneous at low temperature but becomes spontaneous at high temperature. What are the signs for ΔH° and ΔS°, respectively?
What is +,+?
Calculate the equilibrium constant at 25 °C for the following reaction. 2 LiOH(s) + CO2(g) → Li2CO3(s) + H2O(g) ΔG° = -79 kJ/mol rxn.
What is =6.9×1013 ?
What is E˚ for the following balanced reaction?
Zn(s) + Pb2+(aq) → Zn2+(aq) + Pb(s)
Half-reaction Standard Reduction Potential
Zn2+(aq) + 2e– → Zn(s) –0.763
Pb2+(aq) + 2e– → Pb(s) –0.126
What is +0.637 V ?
How many seconds would it take to deposit 30.00 g of Fe (FM 55.845 g/mol) from a 1.50-L vat of molten FeCl3 (FM 162.2 g/mol) onto an electrode using a current of 5.00 A?
Cathode: Fe3+(l) + 3 e- → Fe(s)
Anode: 2 Cl-(l) → Cl2(g) + 2 e- 1.00
What is 3.11×104 𝑠 ?
What concentration of NaF is required to make [OH-] = 4.400×10-11 M in a 0.300 M solution of HF? For HF, Ka = 6.6×10-4.
Determine ΔS for N2O4(g) --> 2NO2(g) given the following information.
Substance S° (J/mol · K)
N2O4(g) 304.3
NO2(g) 240.45
What is +176.7 J/mol · K ?
What is the sign value for ΔS and ΔH for the six phase changes and what value is ΔG at high and low temps?
Fusion + + Low + High -
Freezing - - Low - High +
Evaporation + + Low + High -
Condensation - - Low - High +
Deposition - - Low + high -
Sublimination + + low - High +
Calculate the standard potential, E°, for this reaction from its equilibrium constant at 298 K.
X(s) + Y2+(aq) ⇄ X2+(aq) + Y(s) K = 1.44×10-5
What is −0.143 𝑉 ?
How long would it take to electroplate a flute with 28.3 g of silver (107.87 g/mol) at a constant current of 2.0 amps using AgNO3?
What is 211 min ?