Question

I have two questions here.
1.

Calculate the expected pH when 0.5 mL of 0.1 M HCL is added to 30.0mL pure water. Do the same calculation when the same amount of HClis added to 30.0 mL of your original .05M buffer. Compare thecalculated pH to the actual measured pH.

My buffer solution pH=4.36.

2.
If you have 50 mL of .05M potassium phosphate buffer pH 7.0 and youadded 2.0 mL of 0.1M HCl what would the final pH be? What would thepH be if 2.0 mL of 0.1M NaOH was added to the same amount of theoriginal buffer?
please help