What variables have to be kept the same in this experiment?

Forests and meadows are often cut down to make way for farms or large number of new homes. what are some of the elements of ecosystems that are lost when plants in these areas are removed?

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.

What is a number added in front of a formula in order to balance the equation