What mass of potassium nitrate is needed to generate 179.0 L of gas, composed of 89.00 L of N2 and 90.0 L of O2 at 0.720 atm and 285 K, using these two reactions?

Abeaker with 2.00×102 ml of an acetic acid buffer with a ph of 5.000 is sitting on a benchtop. the total molarity of acid and conjugate base in this buffer is 0.100 m. a student adds 4.70 ml of a 0.360 m hcl solution to the beaker. how much will the ph change? the pka of acetic acid is 4.740.