Oil spreads on water to form a film about 120nm thick(two significant figures). How many square kilometers of ocean will be covered by the slick formed when two barrels of oil are spilled? (1 barrel=31.5 US gallons, 1 gallon=3.79 liters)

Acontrol during an experiment. might change remains constant does not exist does change

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

Complete each row of the table below by filling in the missing prefix or missing exponent.