A chemist titrates 110.0 mL of a 0.4296 M pyridine (C,H,N) solution with 0.6576 M HNO3 solution at 25 °C. Calculate the pH at equivalence. The p K, of pyridine is 8.77.

Define and explain the significance of the equivalence point of a titration. Identify the role of the indicator in this context.

Rainwater is slightly acidic due to dissolved CO₂. Use the following data to calculate the pH of unpolluted rainwater at 22.6°C: vol % in air of CO₂ = 0.063 vol%; solubility of CO2 in pure water at 22.6°C and 1.09 atm is 79.29 mL CO2 per 100 mL, K₁1 of H₂CO3 = 5.27x10-7. Express the pH with 2 decimals. You might have to solve a quadratic.

The curve for the titration of 25.0 mL of 0.100 M C5H5N(aq), pyridine, with 0.100 M HCI(aq) is given below. 12 10 8 4 2 5 10 15 20 25 30 35 Va(mL) (If the image above does not appear, click here.) Estimate the pH at the stoichiometric point. Your answer must contain only one decimal place. 8.8

a buffer has been prepared using 0.1 moles of sodium acetate (NaAc)  and 0.1 moles of acetic acid (HAc), which has been added to 100 ml of water. What is the pH of the solution?

The acid-base indicator "Thymol Blue" has two transition ranges as listed below (with the corresponding acid dissociation constants): 7. Ka AcidColour BaseColour Thymol Blue 1 Thymol Blue 2 2.24 x 102 Red Yellow 1.26 x 10 Yellow Blue What colour would you expect it to be at the following pH values? Briefly justify your answers. (a) (b) (c) (d) 0.9 5.2 7.8 10.7

An analytical chemist is titrating 122.9 mL of a 0.6300M solution of isopropylamine ((CH,) CHNH,) with a 0.3800M solution of HNO3. The p K, of 2 isopropylamine is 3.33. Calculate the pH of the base solution after the chemist has added 233.4 mL of the HNO, solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of HNO, solution added. 3. Round your answer to 2 decimal places.

Calculate the pH of a buffer when 0.010 moles of NaOH is added to 100. mL solution that is 0.20 M sodium pentanoate (C HCOONa) and 0.20 M pentanoic acid (CH₂COOH). PK (CH₂ a COOH) = 4.82.