The volume of a pond being studied for the effects of acid rain is 35 kiloliters (kL). There are 1,000 liters (L) in 1 kL and 1 x 10^6 microliters (mL) in 1 L.
35 kL (1,000 L/ 1kL) (1 x 10^6 microliters / 1 L) = 3.5 x 10^10 microliters
The volume of this pond in microliters is 3.5 x 10^10 microliters