What would the answer be? if you could help that would be a big help ^^

Iwill give extra points to who gets this right

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

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.