Please help me with these questions..​

The kw for water at 0 °c is 0.12× 10–14 m2. calculate the ph of a neutral aqueous solution at 0 °c.

How many grams are in one mole of lead?

An experiment is conducted to see if cats preferred skim milk or 2% milk. a cup of skim milkwas put out for 5 kittens and then measured how much the kittens drank over the course of aday. following a cup of 2% milk was purout for the skittens and then masured how much thekittens drank over the course of a day. the same kittens were used and the milk was served atthe same temperature. it was discovered that the cats liked the 2% milk more than the skimmilk. what is the dependent variable in this experiment?