Explain the Buffer Range and Buffer Capacity?

You have 1.5 liter of solution that is composed of 8.88 grams of NH3 and 11.33 grams of ammonium chloride mixed well. Kb for ammonia =1.8 x 10^-5 (A) is this a buffer solution? Why or why not? (B)if it is a buffer solution, what is the pH of this buffer solution? (C)how many mL of 1.50 M HCl can be added to this solution before the buffer is exhausted (d) how many mL of 1.5 M NaOH can be added to this solution before the buffer is exhausted?

Ff.33.

The pH of unbuffered water, such as rain, is decreasing consistently over time as atmospheric CO2 concentrations increase. a) What will be the atmospheric CO2 level (in ppm) when the pH of rain water reaches 5.50 at 25 °C? b) What would be the pH of buffered water (over CaCO3 limestone at 25 °C) at the CO2 level in part a)? c) Determine the concentrations of HCO3– and CO32– ions in the buffered water of part b) and then determine the alkalinity of the solution in ppm CaCO3.