Question

52) (a) Use the Henderson-Hasselbalch equation to calculate the pt of NH CI and 0.15 M in NHb. (b) How would you prepare an NIH-CI-NHs buffer that has a pll of 9.00 (The Ka for NH, is 1.8 x 10) 53) A buffer solution contains carbonic acid (H:COs) and sodium bicarbonate (NaliCO,), each at a buffer solution that is 045 Mi concentration of 0.100 M. The relevant equilibrium is shown below, What is the pll of this buffer solutiont 54) At 40 °C, the pll of water is 6.77, what is Ion-Product Constant for Water, Kw.at 40 C? 55) If a solution of acetic acid has a pli-2.74 and a pK-4,74, what is the ratio of CH Co,/[CHCO in the solution? Show your calculations the reaction 3H2(g)+Ng)2NHo(g), determine the equilibrium constant at 600C if at this ure, the equilibrium concentrations are: [Na]-4.53 M. (Ha]-249 M, and INH.1-7.62M 56) For t sample of aqueous hydrochloric acid was neutralized with aqueous sodium hydroxide in a the temperature of 100.0 g of water surrounding the reaction increased from 25.0°C to 31.5°C. f 57) When a the specific heat of water is 1.00 cal/(g C), calculat e the quantity of energy in calories involved in this neutralization reaction. 58) How many kJ of heat are needed to raise the temperature of 0.20 kg of water from 20 Cto 100 C in preparing a cup of coffee? (Cwar 4.18 kJ/kg"C) 59) Consider the reversible reaction: A(g) 2B(g) At equilibrium, the concentration of A is 0.381 M and that of B is 0.154 M. What is the value of the equilbium constant, Keq? 60) A candy sample of 1.00 g is completely combusted in a bomb calorimeter. The calorimeter contains 982g of water, and the measured temperature increase is 2.62'C. What is the fuel value of the candy sample in nutritional Calories? [SH.-1.00 calgo] 61) when 50.0 mL of 0.200 MAgNO3 and 50.0 mL of 0.200 M HC1 are mixed in a constant-pressure calorimeter, the temperature of the mixture increases from 23.2 °C to 24.8 °C. The temperature increase is caused by the following reaction: AgNO (aq) +HCag)AgCl)+HNOs(aq) Calculate the enthalpy change (AH) for this reaction in kJ/mol of AgNO,. (Assume that the combined solution has a mass of 100.0 g and a specific heat of 4.18 J/g. C.) 0.100 M HCI is titrated with 0.100 M NaOH. Calculate the phi after the addition of , (d) 40.0 mL, (e) 60.0 mL. A o the volume of added titrant is known as a pHi titration curve. of the pH of the solution as a function of the volume of Using the available data po each of the following volumes of NaoH: 0)00 mL, (6) 100 ml. (e) 200 ml ints, plot the pH titration curve for the above titration. 63-80) Problems in the Homework Assignments for Chapters 7 and 8